EXHIBIT
10.34





November
2, 2009




Andrew
Last


3
Shadewell Court


Danville,
CA 94506





Dear
Andrew:





It is
our  pleasure to offer you the position of Chief Commercial Officer
and Executive Vice President with Affymetrix at an annual salary of $365,000
(bi-weekly $14,038.46), reporting to Kevin King, Chief Executive
Officer.  Your nomination as a Section 16(b) officer for Affymetrix
will be subject to review and approval by our Board of Directors at their next
meeting in January 2010.





In
addition to your annual salary, we are pleased to offer a sign-on bonus in the
amount of $145,000 which will be paid to you in Q1 2010 at the time our Annual
Corporate Bonus payments are made.  Bonus awards are subject to
applicable withholding of taxes and 401(k) contributions (if
enrolled).





Additionally,
we will recommend to the Compensation Committee of the Board of Directors of
Affymetrix that you be granted two equity awards.  The first is a Stock
Option Grant of 90,000 shares of common stock of Affymetrix.  These
options will vest 25% per year over a four (4) year period beginning on the
grant date, and will be granted (and, therefore priced) when approved by the
Compensation Committee.  The second is a grant of 20,000 shares of
restricted shares of common stock of Affymetrix.  These shares are not
stock options, but rather fully paid for shares of restricted stock. These
shares will vest 25% per year over a four (4) year period beginning on the grant
date, provided that you continue to be an employee of Affymetrix on such
anniversary dates.  These restricted shares will be granted when
approved by the Compensation Committee.  The terms of these equity
awards will be governed in all respects by the terms of the applicable
Affymetrix equity incentive plans and the equity award agreements that will be
provided to you after commencement of your employment.





Commencing
January 1, 2010, you will also be eligible to participate in the Affymetrix
Annual Bonus Program with an award level targeted at 50% of annual base
salary.  The actual bonus amount is determined each year by the Board
of Directors based on corporate achievement -- financial performance &
corporate goals -- and your individual goal achievement.





As an
additional condition of employment, we will require that you sign a copy of the
company's Confidentiality and Nondisclosure Agreement.





Federal
Immigration Law requires that all employers verify each individual’s eligibility
to work in the United States, including U.S. citizens.  Your
employment offer is contingent upon your providing satisfactory proof of
identity and authorization to work in the United States.  Please bring
the appropriate original documentation on your first day of work.  A
list of acceptable I-9 documentation is attached for your review.





Your
employment is at will and may be terminated by you or by Affymetrix for any or
no reason, with or without cause or notice.





This
offer is contingent upon satisfactory completion of reference checks and
background checks.





Please
note that the sign-on bonus is deemed earned upon the completion of one year’s
employment.  If you are terminated for cause within one year from your
start date or in the event you voluntarily terminate your employment with
Affymetrix within one year from your start date, your signature at the bottom of
this letter signifies your agreement to reimburse Affymetrix in full before or
on your termination date.  You may also elect to allow Affymetrix to deduct
your sign-on bonus amount from your final paycheck.  (As set forth in Labor
Code Section 2924, in order to establish a termination for cause, there must be
a willful breach of duty, a habitual neglect of duty or a continued incapacity
to perform assigned duties)




In the
event of a termination without cause prior to the bonus payment, you will remain
entitled to the bonus and will receive it on the date referenced above.  In
the event of a termination without cause subsequent to the bonus payout, no
reimbursement of the bonus payment will be required.




If you
have any questions, please feel free to contact me at (408)
731-5622.  To
indicate acceptance of this offer please return a signed copy of this letter to
me by the 3rd business day from the date of this offer, close of
business.  You may fax the letter back to me at (408)
731-5855.





Sincerely,





/s/ Lori
Ciano





Lori
Ciano


Senior
Vice President, Human Resources




Offer
Acceptance:




/s/
      Andrew Last
              
              November
      4, 2009Andrew
      LastDecember
      7, 2009Start
      Date