<PAGE>
                                                                  Exhibit 10.3.4



                                    GUARANTY

                  THIS GUARANTY (this "Guaranty"), is made and entered into as
of February 11, 2002, by MOBILE MINI I, INC., an Arizona corporation, MOBILE
MINI HOLDINGS, INC., a Delaware corporation, DELIVERY DESIGN SYSTEMS, INC., an
Arizona corporation, MOBILE MINI, LLC, a Delaware limited liability company,
MOBILE MINI, LLC, a California limited liability company, MOBILE MINI OF OHIO,
LLC, a Delaware limited liability company, and MOBILE MINI TEXAS LIMITED
PARTNERSHIP, LLP, a Texas limited liability partnership (each, together with
each additional Subsidiary of Mobile Mini, Inc. (the "Borrower") which becomes a
party hereto, a "Guarantor" and collectively, the "Guarantors"), in favor of the
financial institutions and their successors and assigns (the "Lenders") which
may now be or hereafter become parties to the Loan Agreement (as defined below),
and FLEET CAPITAL CORPORATION, for itself and as agent for the Lenders (the
"Agent"; and together with the Lenders, the "Guaranteed Parties").

                                 R E C I T A L S

                  WHEREAS, the Agent, the Lenders and Mobile Mini, Inc., a
Delaware corporation (the "Borrower"), the parent of Guarantors, have entered
into that certain Loan and Security Agreement, dated as of February 11, 2002 (as
the same may be amended, supplemented, amended and restated or otherwise
modified from time to time, the "Loan Agreement"), providing for the extension
of credit by the Lenders to the Borrower;

                  WHEREAS, as wholly-owned subsidiaries of Borrower, each
Guarantor is materially interested in the financial success of Borrower; and

                  WHEREAS, Borrower and Guarantors are involved in an
inter-related business enterprise and will benefit from the financing provided
by the Guaranteed Parties;

                  WHEREAS, the Lenders have required, as a condition to the
extension of credit under the Loan Agreement, that the Guarantors execute and
deliver this Guaranty.

                  NOW, THEREFORE, in consideration of the premises and to induce
the Lenders to extend credit under the Loan Agreement, each Guarantor agrees
with the Agent for its benefit and the ratable benefit of the Lenders as
follows:

                                A G R E E M E N T

                  1.       DEFINITIONS AND CONSTRUCTION.

                           1.1      DEFINITIONS. Capitalized terms used herein
and not otherwise defined herein shall have the meanings ascribed to them in the
Loan Agreement. The following terms, as used in this Guaranty, shall have the
following meanings:


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                                    "GUARANTEED OBLIGATIONS" means the
Obligations owing by Borrower to the Guaranteed Parties, including interest that
accrues after the commencement of a bankruptcy or insolvency proceeding or which
would have accrued but for such proceeding.

                           1.2      CONSTRUCTION. Unless the context of this
Guaranty clearly requires otherwise, references to the plural include the
singular, references to the singular include the plural, and the term
"including" is not limiting. The words "hereof," "herein," "hereby,"
"hereunder," and other similar terms refer to this Guaranty as a whole and not
to any particular provision of this Guaranty. Any reference herein to any of the
Loan Documents includes any and all alterations, amendments, extensions,
modifications, renewals, or supplements thereto or thereof, as applicable.
Neither this Guaranty nor any uncertainty or ambiguity herein shall be construed
or resolved against the Guaranteed Parties or any Guarantor, whether under any
rule of construction or otherwise. On the contrary, this Guaranty has been
reviewed by each Guarantor, each of the Guaranteed Parties, and their respective
counsel, and shall be construed and interpreted according to the ordinary
meaning of the words used so as to fairly accomplish the purposes and intentions
of the Guaranteed Parties and Guarantors.

                  2.       GUARANTEED OBLIGATIONS. Each Guarantor hereby
irrevocably and unconditionally, jointly and severally, guarantees to the
Guaranteed Parties, as and for its own debt, until final and indefeasible
payment thereof has been made, (a) payment of the Guaranteed Obligations, in
each case when and as the same shall become due and payable, whether at
maturity, pursuant to a mandatory prepayment requirement, by acceleration, or
otherwise; it being the intent of such Guarantor that the guaranty set forth
herein shall be a guaranty of payment and not a guaranty of collection; and (b)
the punctual and faithful performance, keeping, observance, and fulfillment by
Borrower of all of the agreements, conditions, covenants, and obligations of
Borrower contained in the Loan Agreement and in each of the other Loan
Documents.

                  The liability of Guarantors under this Guaranty shall be joint
and several and may be enforced against each Guarantor without regard to whether
enforcement is sought or available against any other Guarantor.

                  3.       CONTINUING GUARANTY. This Guaranty includes
Guaranteed Obligations arising under successive transactions continuing,
compromising, extending, increasing, modifying, releasing, or renewing the
Guaranteed Obligations, changing the interest rate, payment terms, or other
terms and conditions thereof, or creating new or additional Guaranteed
Obligations after prior Guaranteed Obligations have been satisfied in whole or
in part. Each Guarantor hereby absolutely, knowingly, unconditionally, and
expressly waives and agrees not to assert any right it has under Section 2815 of
the California Civil Code, or otherwise, to revoke this Guaranty as to future
indebtedness.

                  4.       PERFORMANCE UNDER THIS GUARANTY. In the event that
Borrower fails to make any payment of any Guaranteed Obligations on or before
the due date thereof, or if Borrower shall fail to perform, keep, observe, or
fulfill any other obligation referred to in clause (b) of Section 2 hereof in
the manner provided in the Loan Agreement or the other Loan


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Documents, as applicable, Guarantors immediately shall cause such payment to be
made or each of such obligations to be performed, kept, observed, or fulfilled.

                  5.       PRIMARY OBLIGATIONS. This Guaranty is a primary and
original obligation of each Guarantor and is an absolute, unconditional, and
continuing guaranty of payment and performance which shall remain in full force
and effect without respect to future changes in conditions, including any change
of law. Each Guarantor agrees that it is directly, and jointly and severally
with any other Guarantor of the Guaranteed Obligations, liable to the Guaranteed
Parties, that the obligations of each Guarantor hereunder are independent of the
obligations of Borrower or any other Guarantor, and that a separate action may
be brought against such Guarantor whether such action is brought against
Borrower or any other Guarantor or whether Borrower or any such other guarantor
is joined in such action. Each Guarantor agrees that its liability hereunder
shall be immediate and shall not be contingent upon the exercise or enforcement
by the Guaranteed Parties of whatever remedies they may have against Borrower or
any other Guarantor, or the enforcement of any lien or realization upon any
security the Guaranteed Parties may at any time possess. Each Guarantor agrees
that any release which may be given by any Guaranteed Party to Borrower or any
other Guarantor shall not release such Guarantor. Each Guarantor consents and
agrees that the Guaranteed Parties shall be under no obligation (under Sections
2899 or 3433 of the California Civil Code or otherwise) to marshal any assets of
Borrower or any other Guarantor in favor of such Guarantor, or against or in
payment of any or all of the Guaranteed Obligations.

                  6.       WAIVERS.

                           6.1      Each Guarantor absolutely, unconditionally,
knowingly, and expressly waives:

                                    (a)      (a) notice of acceptance hereof;
(b) notice of any loans or other financial accommodations made or extended under
the Loan Documents or the creation or existence of any Guaranteed Obligations;
(c) notice of the amount of the Guaranteed Obligations, subject, however, to
such Guarantor's right to make inquiry of Agent to ascertain the amount of the
Guaranteed Obligations at any reasonable time; (d) notice of any adverse change
in the financial condition of Borrower or any other Guarantor or of any other
fact that might increase such Guarantor's risk hereunder; (e) notice of
presentment for payment, demand, protest, and notice thereof as to any
instruments among the Loan Documents; (f) notice of any unmatured event of
default or event of default under the Loan Agreement; and (g) all other notices
(except if such notice is specifically required to be given to such Guarantor
hereunder or under any Loan Document to which such Guarantor is a party) and
demands to which such Guarantor might otherwise be entitled.

                                    (b)      its right, under Sections 2845 or
2850 of the California Civil Code, or otherwise, to require the Guaranteed
Parties to institute suit against, or to exhaust any rights and remedies which
the Guaranteed Parties have or may have against, Borrower or any third party, or
against any collateral for the Guaranteed Obligations provided by Borrower, such
Guarantor, or any other Guarantor or any third party. In this regard, such
Guarantor agrees that it is bound to the payment of all Guaranteed Obligations,
whether now existing or hereafter


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accruing, as fully as if such Guaranteed Obligations were directly owing to the
Guaranteed Parties by such Guarantor. Such Guarantor further waives any defense
arising by reason of any disability or other defense (other than the defense
that the Guaranteed Obligations shall have been fully and finally performed and
indefeasibly paid) of Borrower or by reason of the cessation from any cause
whatsoever of the liability of Borrower in respect thereof.

                                    (c)      (a) any rights to assert against
any of the Guaranteed Parties any defense (legal or equitable), set-off,
counterclaim, or claim which such Guarantor may now or at any time hereafter
have against Borrower or any other party liable to such Guaranteed Party; (b)
any defense, set-off, counterclaim, or claim, of any kind or nature, arising
directly or indirectly from the present or future lack of perfection,
sufficiency, validity, or enforceability of the Guaranteed Obligations or any
security therefore or for this Guaranty; (c) any defense such Guarantor has to
performance hereunder, and any right such Guarantor has to be exonerated,
provided by Sections 2819, 2822, or 2825 of the California Civil Code, or
otherwise, arising by reason of: the impairment or suspension of any Guaranteed
Party's rights or remedies against Borrower or any other Guarantor; the
alteration by any Guaranteed Party of the Guaranteed Obligations; any discharge
of the Borrower's or any other Guarantor's obligations to any Guaranteed Party
by operation of law as a result of such Guaranteed Party's intervention or
omission; or the acceptance by any Guaranteed Party of anything in partial
satisfaction of the Guaranteed Obligations; (d) the benefit of any statute of
limitations affecting such Guarantor's liability hereunder or the enforcement
thereof, and any act which shall defer or delay the operation of any statute of
limitations applicable to the Guaranteed Obligations shall similarly operate to
defer or delay the operation of such statute of limitations applicable to such
Guarantor's liability hereunder.

                           6.2      Each Guarantor absolutely, unconditionally,
knowingly, and expressly waives any defense arising by reason of or deriving
from (i) any claim or defense based upon an election of remedies by any of the
Guaranteed Parties including any defense based upon an election of remedies by
any Guaranteed Party under the provisions of Sections 580a, 580b, 580d, and 726
of the California Code of Civil Procedure or any similar law of California or
any other jurisdiction; or (ii) any election by any Guaranteed Party under
Bankruptcy Code Section 1111(b) to limit the amount of, or any collateral
securing, its claim against the Borrower. Pursuant to California Civil Code
Section 2856(b):

                                    "Guarantor waives all rights and defenses
         arising out of an election of remedies by the creditor, even though
         that election of remedies, such as a nonjudicial foreclosure with
         respect to security for a guaranteed obligation, has destroyed the
         guarantor's rights of subrogation and reimbursement against the
         principal by the operation of Section 580(d) of the California Code of
         Civil Procedure or otherwise."

If any of the Guaranteed Obligations or any obligations of a Guarantor hereunder
at any time are secured by a mortgage or deed of trust upon real property, the
Guaranteed Parties may elect, in their sole discretion and except as otherwise
provided in the Loan Documents, upon a default with respect to the Guaranteed
Obligations, to foreclose such mortgage or deed of trust judicially or
nonjudicially in any manner permitted by law, before or after enforcing this
Guaranty, without diminishing or affecting the liability of such Guarantor
hereunder except to the extent the


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Guaranteed Obligations are repaid with the proceeds of such foreclosure. Each
Guarantor understands that (a) by virtue of the operation of California's
antideficiency law applicable to nonjudicial foreclosures, an election by the
Guaranteed Parties nonjudicially to foreclose such a mortgage or deed of trust
probably would have the effect of impairing or destroying rights of subrogation,
reimbursement, contribution, or indemnity of such Guarantor against Borrower or
other guarantors or sureties, and (b) absent the waiver given by such Guarantor
herein, such an election would prevent the Guaranteed Parties from enforcing
this Guaranty against such Guarantor. Understanding the foregoing, and
understanding that each Guarantor is hereby relinquishing a defense to the
enforceability of this Guaranty, each Guarantor hereby waives any right to
assert against any of the Guaranteed Parties any defense to the enforcement of
this Guaranty, whether denominated "estoppel" or otherwise, based on or arising
from an election by the Guaranteed Parties nonjudicially to foreclose any such
mortgage or deed of trust. Each Guarantor understands that the effect of the
foregoing waiver may be that such Guarantor may have liability hereunder for
amounts with respect to which such Guarantor may be left without rights of
subrogation, reimbursement, contribution, or indemnity against Borrower or other
guarantors or sureties. Each Guarantor also agrees that the "fair market value"
provisions of Section 580a of the California Code of Civil Procedure shall have
no applicability with respect to the determination of such Guarantor's liability
under this Guaranty.

                           6.3      To the extent that any Guarantor shall repay
any of the Guaranteed Obligations, it shall be entitled to contribution and
indemnification from, and to be reimbursed by, each other Guarantor, but all
such claims of contributions, indemnification and reimbursement shall be
subordinate in right of payment to the prior indefeasible payment in full, in
cash, of the Guaranteed Obligations. Notwithstanding the foregoing, until such
time as all of the Guaranteed Obligations have been fully, finally, and
indefeasibly paid in full in cash: (a) each Guarantor hereby postpones any right
of subrogation such Guarantor has or may have as against Borrower or any other
Guarantor of the Obligations of Borrower with respect to the Guaranteed
Obligations; (b) each Guarantor hereby postpones any right to proceed against
Borrower or any other Guarantor or any other Person, now or hereafter, for
contribution, indemnity, reimbursement, or any other suretyship rights and
claims, whether direct or indirect, liquidated or contingent, whether arising
under express or implied contract or by operation of law, which such Guarantor
may now have or hereafter have as against Borrower or any other Guarantor with
respect to the Guaranteed Obligations; and (c) each Guarantor also hereby
postpones any right to proceed or seek recourse against or with respect to any
property or asset of Borrower or any other Guarantor.

                           6.4      WITHOUT LIMITING THE GENERALITY OF ANY OTHER
WAIVER OR OTHER PROVISION SET FORTH IN THIS GUARANTY, EACH GUARANTOR HEREBY
ABSOLUTELY, KNOWINGLY, UNCONDITIONALLY, AND EXPRESSLY WAIVES AND AGREES NOT TO
ASSERT ANY AND ALL BENEFITS OR DEFENSES ARISING DIRECTLY OR INDIRECTLY UNDER ANY
ONE OR MORE OF CALIFORNIA CIVIL CODE SECTIONS 2799, 2808, 2809, 2810, 2815,
2819, 2820, 2821, 2822, 2825, 2839, 2845, 2848, 2849, AND 2850, CALIFORNIA CODE
OF CIVIL PROCEDURE SECTIONS 580a, 580b, 580c, 580d, AND 726, AND CHAPTER 2 OF
TITLE 14 OF THE CALIFORNIA CIVIL CODE.


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                  7.       RELEASES. Each Guarantor consents and agrees that,
without notice to or by such Guarantor and without affecting or impairing the
obligations of such Guarantor hereunder, the Guaranteed Parties may, by action
or inaction and in accordance with any applicable provisions of the Loan
Documents:

                           7.1      compromise, settle, extend the duration or
the time for the payment of, or discharge the performance of, or may refuse to
or otherwise not enforce the Loan Documents;

                           7.2      release all or any one or more parties to
any one or more of the Loan Documents or grant other indulgences to Borrower in
respect thereof;

                           7.3      amend or modify in any manner and at any
time (or from time to time) any of the Loan Documents; or

                           7.4      add (or fail to add), release or substitute
any other guarantor, if any, of the Guaranteed Obligations, or enforce,
exchange, release (by action or inaction), or waive any security for the
Guaranteed Obligations (including, the collateral referred to in Section 14
hereof) or any other guaranty of the Guaranteed Obligations, or any portion
thereof.

                  8.       NO ELECTION. The Guaranteed Parties shall have the
right to seek recourse against each Guarantor to the fullest extent provided for
herein, and no election by any Guaranteed Party to proceed in one form of action
or proceeding, or against any party, or on any obligation, shall constitute a
waiver of the Guaranteed Parties' right to proceed in any other form of action
or proceeding or against other parties unless the Guaranteed Parties have
expressly waived such right in writing. Specifically, but without limiting the
generality of the foregoing, no action or proceeding by any Guaranteed Party
under any document or instrument evidencing the Guaranteed Obligations shall
serve to diminish the liability of any Guarantor under this Guaranty except to
the extent that the Guaranteed Parties finally and unconditionally shall have
realized indefeasible payment by such action or proceeding.

                  9.       INDEFEASIBLE PAYMENT. The Guaranteed Obligations
shall not be considered indefeasibly paid for purposes of this Guaranty unless
and until all payments to the Guaranteed Parties are no longer subject to any
right on the part of any person, including Borrower, Borrower as a debtor in
possession, or any trustee (whether appointed under the Bankruptcy Code or
otherwise) of Borrower's assets to invalidate or set aside such payments or to
seek to recoup the amount of such payments or any portion thereof, or to declare
same to be fraudulent or preferential. In the event that, for any reason, any
portion of such payments to the Guaranteed Parties is set aside or restored,
whether voluntarily or involuntarily, after the making thereof, then the
obligation intended to be satisfied thereby shall be revived and continued in
full force and effect as if said payment or payments had not been made, and the
Guarantors shall be liable for the full amount the Guaranteed Parties are
required to repay plus any and all reasonable out-of-pocket costs and expenses
(including attorneys' fees) paid by the Guaranteed Parties in connection
therewith.


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                  10.      SUBORDINATION. Each Guarantor hereby agrees that any
and all present and future indebtedness of Borrower owing to such Guarantor is
postponed in favor of and subordinated to payment, in full, in cash, of the
Guaranteed Obligations. In this regard, no payment of any kind whatsoever, other
than payments consistent with the past practices of Borrower or otherwise
consented to by Agent, which consent shall not be unreasonably withheld, shall
be made with respect to such indebtedness until the Guaranteed Obligations have
been paid in full.

                  11.      PAYMENTS; APPLICATION. All payments to be made
hereunder by each Guarantor shall be made in lawful money of the United States
of America at the time of payment, shall be made in immediately available funds,
and shall be made without deduction (whether for taxes or otherwise) or offset.
All payments made by each Guarantor hereunder shall be applied as follows:
first, to all reasonable out-of-pocket costs and expenses (including attorneys'
fees) incurred by the Guaranteed Parties in enforcing this Guaranty or in
collecting the Guaranteed Obligations; second, to all accrued and unpaid
interest, premium, if any, and fees owing to the Guaranteed Parties constituting
Guaranteed Obligations; and third, to the balance of the Guaranteed Obligations.

                  12.      INDEMNIFICATION. Each Guarantor agrees to indemnify
each of the Guaranteed Parties and hold each of the Guaranteed Parties harmless
against all obligations, demands, or liabilities asserted by any party and
against all losses in any way suffered, incurred, or paid by any Guaranteed
Party as a result of or in any way arising in connection with this Agreement,
unless such obligations, demand, liabilities or losses shall be due to willful
misconduct or gross negligence on the part of such Guaranteed Party.

                  13.      BOOKS AND RECORDS. Each Guarantor agrees that the
Guaranteed Parties' books and records showing the account between the Guaranteed
Parties and Borrower shall be admissible in any action or proceeding and shall
be binding upon such Guarantor for the purpose of establishing the items therein
set forth and shall constitute prima facie proof thereof.

                  14.      COLLATERAL. The obligations of each Guarantor
hereunder are secured, as provided in the Subsidiary Security Agreement, of even
date herewith, executed by such Guarantor in favor of the Agent, and the other
Loan Documents to which such Guarantor is a party.

                  15.      RIGHT OF SETOFF. Except to the extent prohibited by
applicable law, and in addition to and not in limitation of all rights of offset
that any Guaranteed Party or other holder of a Note may have under applicable
law or under any Loan Documents, each Guaranteed Party or other holder of a Note
shall upon the occurrence of any Event of Default and whether or not such
Guaranteed Party or such holder has made any demand or the Guarantors'
obligations are matured, have the right to appropriate and apply to the payment
of the Guarantors' obligations hereunder, all deposits (general or special, time
or demand, provisional or final) then or thereafter held by and other
indebtedness or property then or thereafter owing by such Guaranteed Party or
other holder to the Guarantors, whether or not related to this Guaranty or any
transaction hereunder.


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                  16.      AMENDMENTS. Any amendment or waiver of any provision
of this Guaranty and any consent to any departure by any Guarantor from any
provision of this Guaranty shall be effective only if made or given in
compliance with all of the terms and provisions of Section 11.10 of the Loan
Agreement.

                  17.      EXPENSES. Each Guarantor shall promptly pay to the
Agent, for the ratable benefit of the Guaranteed Parties, the amount of any and
all reasonable out-of-pocket costs and expenses of the Guaranteed Parties (both
before and after the execution hereof) in connection with any matters
contemplated by or arising out of this Guarantee or any of the Loan Documents
whether (a) to prepare, negotiate or execute (i) any amendment to, modification
of or extension of this Guaranty or any other Loan Document to which such
Guarantor is a party or (ii) any instrument, document or agreement in connection
with any sale or attempted sale of any interest herein to any participant, (b)
to commence, defend, or intervene in any litigation or to file a petition,
complaint, answer, motion or other pleadings necessary to protect or enforce the
rights of the Guaranteed Parties under this Guaranty or any other Loan Document,
(c) to take any other action in or with respect to any suit or proceeding
(bankruptcy or otherwise) necessary to protect the rights of the Guaranteed
Parties under this Guaranty or any other Loan Document or to respond to any
subpoena, deposition or interrogatory with respect to any litigation involving
such Guarantor, or (d) to attempt to enforce or to enforce any rights of the
Guaranteed Parties to collect any of the Guaranteed Obligations, including all
reasonable out-of-pocket fees and expenses of attorneys and paralegals
(including charges for inside counsel).

                  18.      HEADINGS. The headings in this Guaranty are for
purposes of reference only and shall not otherwise affect the meaning or
construction of any provision of this Guaranty.

                  19.      SEVERABILITY. The provisions of this Guaranty are
severable, and if any clause or provision shall be held invalid or unenforceable
in whole or in part in any jurisdiction, then such invalidity or
unenforceability shall affect in that jurisdiction only such clause or
provision, or part thereof, and shall not in any manner affect such clause or
provision in any other jurisdiction or any other clause or provision of this
Guaranty in any jurisdiction.

                  20.      NOTICES. All notices, approvals, consents or other
communications to Agent required or desired to be given hereunder shall be in
the form and manner, and delivered to Agent at its addresses, as set forth in
Section 12.8 of the Loan Agreement. All notices, approvals, consents or other
communications to Guarantors required or desired to be given hereunder shall be
in the form and manner, and delivered to Borrower at its addresses, as set forth
in Section 12.8 of the Loan Agreement.

                  21.      REMEDIES CUMULATIVE. Each right, power and remedy of
the Guaranteed Parties provided in this Guaranty or now or hereafter existing at
law or in equity or by statute or otherwise shall be cumulative and concurrent
and shall be in addition to every other right, power or remedy provided for in
this Guarantee or now or hereafter existing at law or in equity or by statute or
otherwise. The exercise or partial exercise by the Guaranteed Parties of any one
or more of such rights, powers or remedies shall not preclude the simultaneous
or later exercise by the Guaranteed Parties of all such other rights, powers or
remedies, and no failure or delay on the


                                      Pg.8
<PAGE>
part of the Guaranteed Parties to exercise any such right, power or remedy shall
operate as a waiver thereof.

                  22.      FINAL EXPRESSION. This Guaranty, together with any
other agreement executed in connection herewith, is intended by the parties as a
final expression of the Guaranty and is intended as a complete and exclusive
statement of the terms and conditions thereof. Acceptance of or acquiescence in
a course of performance rendered under this Guaranty shall not be relevant to
determine the meaning of this Guaranty even though the accepting or acquiescing
party had knowledge of the nature of the performance and opportunity for
objection.

                  23.      ASSIGNABILITY. This Guaranty shall be binding on each
of the Guarantors and its successors and permitted assigns and shall inure to
the benefit of the Guaranteed Parties and their respective successors,
transferees, endorsees and assigns. The Guarantors may not assign this Guaranty.

                  24.      NON-WAIVER. The failure of the Guaranteed Parties to
exercise any right or remedy hereunder, or promptly to enforce any such right or
remedy, shall not constitute a waiver thereof, nor give rise to any estoppel
against the Guaranteed Parties, nor excuse the Guarantors from their obligations
hereunder.

                  25.      TERMINATION; REINSTATEMENT. Except as otherwise
provided herein, this Guaranty shall terminate upon the receipt by each of the
Guaranteed Parties of evidence satisfactory to it of the payment (or prepayment)
in full of the Guaranteed Obligations and any other amounts which may be owing
hereunder and termination of the Lenders' Revolving Loan Commitment. At the time
of such termination, the Guaranteed Parties, at the request and expense of the
Guarantors, will promptly execute and deliver to the Guarantors a proper
instrument or instruments acknowledging the satisfaction and termination of this
Guaranty and such other documents as may be reasonably requested by Guarantors.
To the maximum extent permitted by law, this Guaranty shall continue to be
effective or be reinstated, as the case may be, if at any time any amount
received by Agent or any Lender in respect of the Guaranteed Obligations is
rescinded or must otherwise be restored or returned by Agent or any Lender upon
the insolvency, bankruptcy, dissolution, liquidation or reorganization of any
Guarantor or any other Person or upon the appointment of any receiver,
intervenor, conservator, trustee or similar official for any Guarantor or any
other Person or any substantial part of its assets, or otherwise, all as though
such payments had not been made.

                  26.      COUNTERPARTS. This Guaranty may be executed in any
number of counterparts and by the different parties hereto on separate
counterparts, each of which, when so executed and delivered, shall be an
original, but all of which shall together constitute one and the same agreement.

                  27.      GOVERNING LAW. THE VALIDITY, INTERPRETATION AND
ENFORCEMENT OF THIS GUARANTY AND ANY DISPUTE ARISING OUT OF OR IN CONNECTION
WITH THIS GUARANTY, WHETHER SOUNDING IN CONTRACT, TORT, EQUITY OR OTHERWISE,
SHALL BE GOVERNED BY THE INTERNAL LAWS (AS


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<PAGE>
OPPOSED TO THE CONFLICTS OF LAWS PROVISIONS) AND DECISIONS OF THE STATE OF
CALIFORNIA.

                  28.      SUBMISSION TO JURISDICTION. ALL DISPUTES AMONG THE
GUARANTORS AND THE LENDERS (OR THE AGENT ACTING ON THEIR BEHALF) ARISING UNDER
THIS AGREEMENT, WHETHER SOUNDING IN CONTRACT, TORT, EQUITY OR OTHERWISE, SHALL
BE RESOLVED ONLY BY STATE AND FEDERAL COURTS LOCATED IN LOS ANGELES, CALIFORNIA,
AND THE COURTS TO WHICH AN APPEAL THEREFROM MAY BE TAKEN; PROVIDED, HOWEVER,
THAT THE AGENT, ON BEHALF OF THE LENDERS, SHALL HAVE THE RIGHT, TO THE EXTENT
PERMITTED BY APPLICABLE LAW, TO PROCEED AGAINST ANY OF THE GUARANTORS OR THEIR
PROPERTY IN ANY LOCATION REASONABLY SELECTED BY THE AGENT IN GOOD FAITH TO
ENABLE THE AGENT TO REALIZE ON SUCH PROPERTY, OR TO ENFORCE A JUDGMENT OR OTHER
COURT ORDER IN FAVOR OF THE AGENT. EACH OF THE GUARANTORS WAIVES ANY OBJECTION
THAT IT MAY HAVE TO THE LOCATION OF THE COURT IN WHICH THE AGENT HAS COMMENCED A
PROCEEDING ARISING UNDER THIS AGREEMENT, INCLUDING, WITHOUT LIMITATION, ANY
OBJECTION TO THE LAYING OF VENUE OR BASED ON FORUM NON CONVENIENS.

                  29.      SERVICE OF PROCESS. THE GUARANTORS HEREBY IRREVOCABLY
DESIGNATE CT CORPORATIONS SYSTEMS AS THE DESIGNEE, APPOINTEE AND AGENT OF THE
GUARANTORS TO RECEIVE, FOR AND ON BEHALF OF THE GUARANTORS, SERVICE OF PROCESS
IN SUCH RESPECTIVE JURISDICTIONS IN ANY LEGAL ACTION OR PROCEEDING WITH RESPECT
TO THIS LOAN AGREEMENT OR ANY OTHER LOAN DOCUMENT. IT IS UNDERSTOOD THAT A COPY
OF SUCH PROCESS SERVED ON SUCH AGENT AT ITS ADDRESS WILL BE PROMPTLY FORWARDED
BY MAIL TO THE BORROWER, BUT FAILURE OF ANY OF THE GUARANTORS TO RECEIVE SUCH
COPY SHALL NOT AFFECT IN ANY WAY THE SERVICE OF SUCH PROCESS.

                  30.      JURY TRIAL. THE GUARANTORS, THE AGENT AND THE LENDERS
EACH HEREBY WAIVE ANY RIGHT TO A TRIAL BY JURY. INSTEAD, ANY DISPUTES WILL BE
RESOLVED IN A BENCH TRIAL.

                  31.      LIMITATION OF LIABILITY. NEITHER THE AGENT NOR ANY
LENDER SHALL HAVE ANY LIABILITY TO THE GUARANTORS (WHETHER SOUNDING IN TORT,
CONTRACT, OR OTHERWISE) FOR LOSSES SUFFERED BY ANY OF THE GUARANTORS IN
CONNECTION WITH, ARISING OUT OF, OR IN ANY WAY RELATED TO THE TRANSACTIONS OR
RELATIONSHIPS CONTEMPLATED BY THIS GUARANTY, OR ANY ACT, OMISSION OR EVENT
OCCURRING IN CONNECTION THEREWITH, UNLESS IT IS DETERMINED BY A FINAL AND
NONAPPEALABLE JUDGMENT OR COURT ORDER BINDING ON THE AGENT OR ANY SUCH LENDER,
THAT THE LOSSES WERE THE RESULT OF ACTS OR OMISSIONS CONSTITUTING GROSS
NEGLIGENCE OR WILLFUL MISCONDUCT.


                                     Pg.10
<PAGE>
                  32.      MAXIMUM GUARANTEED AMOUNT. Notwithstanding any other
provision of this Guaranty to the contrary, if and to extent that the
obligations of a Guarantor hereunder would otherwise be held or determined by a
court of competent jurisdiction in any action or proceeding involving any state
corporate law or any state or Federal bankruptcy, insolvency, reorganization,
moratorium, fraudulent conveyance or other law affecting the rights of creditors
generally, to be void, invalid or unenforceable to any extent on account of the
amount of such Guarantor's liability under this Guaranty, giving effect to the
rights of subrogation, contribution, reimbursement and indemnification of such
Guarantor, if any, then notwithstanding any other provision of this Guaranty to
the contrary, the amount of the liability of such Guarantor shall, without any
further action by such Guarantor or any other Person, be automatically limited
and reduced to the highest amount which is valid and enforceable as determined
in such action or proceeding. Each Guarantor agrees that the Guaranteed
Obligations may at any time and from time to time exceed such maximum liability
without impairing this Guaranty or the rights and remedies of any Guaranteed
Party.

                  33.      WAIVERS, CONSENTS. Each Guarantor warrants and agrees
that each of the waivers and consents set forth herein is made after
consultation with legal counsel and with full knowledge of its significance and
consequence, with the understanding that events giving rise to any defense or
right waived may diminish, destroy, or otherwise adversely affect rights which
such Guarantor otherwise may have against Borrower, the Guaranteed Parties, or
others, or against any collateral, and that, under the circumstances, the
waivers and consents herein given are reasonable and not contrary to public
policy or law. If any of the waivers or consents herein are determined to be
unenforceable under applicable law, such waivers and consents shall be effective
to the maximum extent permitted by law.


                                     Pg.11
<PAGE>
                  34.      Additional Guarantors. From time to time subsequent
to the date hereof, additional Subsidiaries of any Guarantor may become parties
hereto as additional Guarantors (the "Additional Guarantors"), by executing a
counterpart (the "Counterpart") substantially in the form of Exhibit A hereto.
Upon delivery of any such Counterpart to the Agent, notice of which is hereby
waived by Guarantors, each such Additional Guarantor shall be a Guarantor and
shall be as fully a party hereto as if such Additional Guarantor were an
original signatory hereto. Each Guarantor expressly agrees that its obligations
arising hereunder shall not be affected or diminished by the addition or release
of any other Guarantor hereunder, nor by any election of Agent not to cause any
Subsidiary of Guarantors to become an Additional Guarantor hereunder. This
Agreement shall be fully effective as to any Guarantor that is or becomes a
party hereto regardless of whether any other Person becomes or fails to become
or ceases to be a Guarantor hereunder.

                  35.      Interpretation of Agreement. Time is of the essence
in each provision of this Agreement of which time is an element. All terms not
defined herein or in the Loan Agreement shall have the meaning set forth in the
applicable Uniform Commercial Code, except where the context otherwise requires.
To the extent a term or provision of this Agreement conflicts with the Loan
Agreement, the Loan Agreement shall control with respect to the subject matter
of such term or provision. Acceptance of or acquiescence in a course of
performance rendered under this Agreement shall not be relevant in determining
the meaning of this Agreement even though the accepting or acquiescing party had
knowledge of the nature of the performance and opportunity for objection


                                     Pg.12
<PAGE>
                  IN WITNESS WHEREOF, each of the Guarantors has executed and
delivered this Guaranty as of the date set forth in the first paragraph hereof.

                                    GUARANTORS:

                                    MOBILE MINI I, INC.,
                                    an Arizona corporation

                                      /s/ Lawrence Trachtenberg
                                      Title: Executive Vice President

                                    MOBILE MINI HOLDINGS, INC.,
                                    a Delaware corporation

                                      /s/ Lawrence Trachtenberg
                                      Title: President

                                    DELIVERY DESIGN SYSTEMS, INC.,
                                    an Arizona corporation

                                      /s/ Lawrence Trachtenberg
                                      Title: Executive Vice President

                                    MOBILE MINI, LLC,
                                    a Delaware limited liability company

                                      /s/ Lawrence Trachtenberg
                                      Title: Executive Vice President and CFO

                                    MOBILE MINI, LLC,
                                    a California limited liability company

                                      /s/ Lawrence Trachtenberg
                                      Title: Executive Vice President and CFO

                                    MOBILE MINI OF OHIO, LLC,
                                    a Delaware limited liability company

                                      /s/ Lawrence Trachtenberg
                                      Title: Executive Vice President and CFO



<PAGE>
                                    MOBILE MINI TEXAS LIMITED
                                    PARTNERSHIP, LLP,
                                    a Texas limited liability partnership

                                      /s/ Lawrence Trachtenberg
                                      Title: Treasurer



<PAGE>
                                                                    EXHIBIT A TO
                                                                        GUARANTY

                              [FORM OF COUNTERPART]

                                   COUNTERPART

                  COUNTERPART (this "Counterpart"), dated _______, is delivered
pursuant to Section 34 of the Guaranty referred to below. The undersigned hereby
agrees that this Counterpart may be attached to the Guaranty, dated as of
February 11, 2002 (as it may be from time to time amended, modified or
supplemented, the "Guaranty"; capitalized terms used herein not otherwise
defined herein shall have the meanings ascribed therein), by Mobile Mini I,
Inc., an Arizona corporation, Mobile Mini Holdings, Inc., a Delaware
corporation, Delivery Design Systems, Inc., an Arizona corporation, Mobile Mini,
LLC, a Delaware limited liability company, Mobile Mini, LLC, a California
limited liability company, Mobile Mini of Ohio, LLC, a Delaware limited
liability company, and Mobile Mini Texas Limited Partnership, LLP, a Texas
limited liability partnership, in favor of Fleet Capital Corporation, for itself
and as agent (the "Agent"). The undersigned by executing and delivering this
Counterpart hereby becomes a Guarantor under the Guaranty in accordance with
Section 34 thereof and agrees to be bound by all of the terms thereof.



                                    [NAME OF ADDITIONAL GUARANTOR]



                                    By:_________________________________________

                                          Name:_________________________________
                                          Title:________________________________