**United
States Securities and Exchange Commission**

**Washington,
D.C. 20549**

**Form
10-QSB**

(Mark
      One)x
    **QUARTERLY
      REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
      1934**
For the
quarterly period ended March 31, 2005

o
    **TRANSITION
      REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
      1934**

For the
transition period from _______ to _______

Commission
file number 333-105811

**ATLAS
AMERICA PUBLIC #12-2003 Limited Partnership**
(Name of
small business issuer in its charter)

**Delaware**
    
    **54-2113989**(State
      or other jurisdiction of incorporation or organization)
    
    (I.R.S.
      Employer311
      Rouser Road
    
    Identification
      No.)Moon
      Township, PA
    
    15108(Address
      of principal executive offices)
    
    (Zip
      code)

Issuer’s
telephone number, including area code: **(412)
262-2830**

Check
whether the issuer (1) filed all reports required to be filed by Section 13 or
15(d) of the Exchange Act during the past 12 months (or for such shorter period
that the registrant was required to file such reports), and (2) has been subject
to such filing requirements for the past 90 days. Yes x      No  o

Indicate
by check mark whether the registrant is an accelerated filer (as defined in Rule
12b-2 of the Exchange Act). Yes  o     No x


1
****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**INDEX TO QUARTERLY REPORT**
**ON FORM 10QSB**


**PAGE****PART
      I.**
    **FINANCIAL INFORMATION**Item
      1.
    Financial StatementsBalance Sheets as of March 31, 2005 and December 31, 2004
      (Unaudited)
    3Statements of Operations for the Three Months ended
      March 31, 2005 and 2004 (Unaudited)
    4Statement of Partners’ Capital Accounts for the Three
      Months ended March 31, 2005 (Unaudited)
    5Statements of Cash Flows for the Three Months ended March 31,
      2005 and 2004 (Unaudited)
    6Notes to Financial Statements
(Unaudited)
    7 -
      9Item
      2.
    Management’s Discussion and Analysis of Financial
      Condition and Results of Operations
    9 -
      12Item
      3.
    Controls and Procedures
    12**PART
      II.**
    **OTHER INFORMATION**Item
      6.
    Exhibits
    12**SIGNATURES**
    13**CERTIFICATIONS**
    14
      - 17

2
Table of Contents**PART I**


**ITEM 1.** **FINANCIAL
STATEMENTS**
****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**BALANCE SHEETS**


**March
      31,**
    
    **December
      31,****2005**
    
    **2004**(Unaudited)
    
    (Audited)**ASSETS**Current
      Assets:Cash
      and cash equivalents
    
    $
    2,471,700
    
    $
    1,024,500Accounts
      receivable - affiliate
    
    
    3,453,000
    
    
    4,616,600Total
      current assets
    
    
    5,924,700
    
    
    5,641,100Oil
      and gas properties (successful efforts)
    
    
    52,218,500
    
    
    52,218,500Less
      accumulated depletion and depreciation
    
    
    (7,711,400
    )
    
    (5,936,300
    )44,507,100
    
    
    46,282,200$
    50,431,800
    
    $
    51,923,300**LIABILITIES
      AND PARTNERS’ CAPITAL**Current
      liabilities:Accrued
      liabilities
    
    $
    25,500
    
    $
    20,400Total
      current liabilities
    
    
    25,500
    
    
    20,400Asset
      retirement obligation
    
    
    1,203,200
    
    
    1,185,400Partners’
      capital:Managing
      General Partner
    
    
    11,870,300
    
    
    11,945,500Limited
      Partners (4,024.015 units)
    
    
    37,332,800
    
    
    38,772,00049,203,100
    
    
    50,717,500$
    50,431,800
    
    $
    51,923,300


The accompanying notes are an integral part of this financial
statement****

3
Table of Contents
****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**STATEMENTS OF OPERATIONS**
**(Unaudited)**


**Three
      Months Ended**
    
    **Three
      Months Ended****March
      31,**
    
    **March
      31,****2005**
    
    **2004****REVENUES:**Natural
      gas and oil sales
    
    $
    3,832,800
    
    **$**
    ****506,700Interest
      income
    
    
    6,100
    
    
    -Total revenues
    
    
    3,838,900
    
    
    506,700**COSTS
      AND EXPENSES:**Production
      expenses
    
    
    415,800
    
    
    51,500Depletion
      and depreciation of oil and gas properties
    
    
    1,775,100
    
    
    2,206,100Accretion
      of asset retirement obligation
    
    
    17,800
    
    
    3,800General
      and administrative expenses
    
    
    56,800
    
    
    17,100Total expenses
    
    
    2,265,500
    
    
    2,278,500**Net
      earnings (loss)**
    
    $
    1,573,400
    
    $
    (1,771,800
    )**Allocation
      of net earnings (loss):**Managing general
      partner
    
    $
    926,500
    
    $
    (142,500
    )Limited partners
    
    $
    646,900
    
    $
    (1,629,300
    )Net earnings (loss) per limited
      partnership unit
    
    $
    161
    
    $
    (405
    )


The accompanying notes are an integral part of this financial
statement****4
Table of Contents
****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**STATEMENTS OF PARTNERS’ CAPITAL
ACCOUNTS**
**FOR THREE MONTHS ENDED March 31, 2005**
**(Unaudited)**
****

**Managing****General**
    
    **Limited****Partner**
    
    **Partners**
    
    **Total****Balance
      at January 1, 2005**
    
    $
    11,945,500
    
    $
    38,772,000
    
    $
    50,717,500Participation
      in revenues and expenses:Net
      production revenues
    
    
    1,195,900
    
    
    2,221,100
    
    
    3,417,000Interest
      income
    
    
    2,100
    
    
    4,000
    
    
    6,100Depletion
      and depreciation
    
    
    (245,400
    )
    
    (1,529,700
    )
    
    (1,775,100
    )Accretion
      of asset retirement obligation
    
    
    (6,200
    )
    
    (11,600
    )
    
    (17,800
    )General
      and administrative
    
    
    (19,900
    )
    
    (36,900
    )
    
    (56,800
    )Net
      earnings
    
    
    926,500
    
    
    646,900
    
    
    1,573,400Distributions
    
    
    (1,001,700
    )
    
    (2,086,100
    )
    
    (3,087,800
    )**Balance
      at March 31, 2005**
    
    $
    11,870,300
    
    $
    37,332,800
    
    $
    49,203,100

The accompanying notes are an integral part of this financial
statement5
Table of Contents

****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**STATEMENT OF CASH FLOWS**
**(Unaudited)**
****

**Three
      Months Ended**
    
    **Three
      Months Ended****March
      31,**
    
    **March
      31,****2005**
    
    **2004****Cash
      flows from operating activities:**Net
      earnings (loss)
    
    $
    1,573,400
    
    $
    (1,771,800
    )Adjustments
      to reconcile net earnings (loss) to net cash provided by operating
      activities:Depletion and
      depreciation
    
    
    1,775,100
    
    
    2,206,100Accretion of asset retirement
      obligation
    
    
    17,800
    
    
    3,800Decrease (Increase) in accounts
      receivable - affiliate
    
    
    1,163,600
    
    
    (388,200
    )Increase in accrued
      liabilities
    
    
    5,100
    
    
    2,900Net
      cash provided by operating activities
    
    
    4,535,000
    
    
    52,800**Cash
      flows from investing activities:**Additional
      limited partner contribution
    
    
    -
    
    
    1,800Net
      cash provided by investing activities
    
    
    -
    
    
    1,800**Cash
      flows from financing activities:**Partners
      distribution
    
    
    (3,087,800
    )
    
    -Capital
      expeditures
    
    
    -
    
    
    (1,900
    )Net
      cash used in financing activities
    
    
    (3,087,800
    )
    
    (1,900
    )Net
      increase in cash and cash equivalents
    
    
    1,447,200
    
    
    52,700Cash
      and cash equivalents at beginning of period
    
    
    1,024,500
    
    
    100Cash
      and cash equivalents at end of period
    
    $
    2,471,700
    
    $
    52,800

The accompanying notes are an integral part of this financial
statement****6
Table of Contents
****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**NOTES TO FINANCIAL STATEMENTS**
**March 31, 2005**
**(Unaudited)**

**NOTE 1****-****BASIS OF
PRESENTATION**

The financial statements of Atlas America Public #12-2003 Limited
Partnership (the Partnership) as of and for the three months ended March 31,
2005 and 2004 are unaudited. Certain information and footnote disclosures
normally included in financial statements prepared in accordance with accounting
principles generally accepted in the United States of America have been
condensed or omitted in this Form 10-QSB pursuant to the rules and regulations
of the Securities and Exchange Commission. However, in the opinion of
management, these interim financial statements include all the necessary
adjustments to fairly present the results of the interim periods presented. The
unaudited interim financial statements should be read in conjunction with the
audited financial statements included in the Partnership’s Form 10-KSB for the
year ended December 31, 2004. The results of operations for the three months
ended March 31, 2005 may not necessarily be indicative of the results of
operations for the year ending December 31, 2005.

**NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING
POLICIES**

In addition to matters discussed further in this note, the
Partnership’s significant accounting policies are detailed in its audited
financial statements and notes thereto in the Partnership’s annual report on
Form 10-K for the year ended December 31, 2004 filed with the Securities and
Exchange Commission.

**Recently Issued Financial Accounting Standards**

In April 2005, the Financial Accounting Standards Board (“FASB”)
issued FASB Interpretation No. 47, Accounting for Conditional Assets Retirement
Obligations (“FIN 47”), which will result in (a) more consistent recognition of
liabilities relating to asset retirement obligations, (b) more information about
expected future cash outflows associated with those obligations, and (c) more
information about investments in long-lived assets because additional asset
retirement cost will be recognized as part of the carrying amounts of the
assets. FIN 47 clarifies that the term conditional asset retirement obligation
as used in Statement of Financial Accounting Standards (“SFAS”) No. 143,
Accounting for Asset Retirement Obligations, refers to a legal obligation to
perform an asset retirement activity in which the timing and (or) method of
settlement are conditional on a future event that may or may not be within the
control of the entity. The obligation to perform the asset retirement activity
is unconditional even though uncertainty exists about the timing and (or) method
of settlement. Uncertainty about the timing and (or) method of settlement of a
conditional asset retirement obligation should be factored into the measurement
of the liability when sufficient information exists.

FIN 47 also clarifies when an entity would have sufficient
information to reasonably estimate the fair value of an asset retirement
obligation. FIN 47 is effective no later than the end of fiscal years ending
after December 15, 2005. Retrospective application of interim financial
information is permitted but is not required. Early adoption of this
interpretation is encouraged. As FIN 47 was recently issued, the Company has not
determined whether the interpretation will have a significant adverse effect on
its financial position or results of operations.

**Fair Value of Financial Instruments**

For cash and cash
equivalents, receivables and payables, the carrying amounts approximate fair
value because of the short maturity of these instruments.

7
Table of Contents
****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**NOTES TO FINANCIAL STATEMENTS**
**March 31, 2005**
**(Unaudited)**

**NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES -
(Continued)**

**Asset Retirement Obligation**
****

The Partnership accounts for the estimated plugging and
abandonment costs of the oil and gas properties in accordance with Statement of
Financial Accounting Standards (“SFAS”) No. 143, “Accounting for Asset
Retirement Obligations.”

A reconciliation of
the Partnership’s liability for plugging and abandonment costs for the three
months ending March 31, 2005 and 2004 is as follows:

**2005**
    
    **2004**Asset
      retirement obligation at beginning of period
    
    $
    1,185,400
    
    $
    -Adoption
      of SFAS No. 143
    
    
    -
    
    
    256,200Accretion
      expense
    
    
    17,800
    
    
    3,800Total
      asset retirement obligation at end of period
    
    $
    1,203,200
    
    $
    260,000

8
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****
**ATLAS AMERICA PUBLIC #12-2003 Limited
Partnership**
**(A Delaware Limited Partnership)**
**NOTES TO FINANCIAL STATEMENTS**
**March 31, 2005**
**(Unaudited)**

**NOTE 2 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES -
(Continued)**

**Supplemental Cash Flow Information**

The Partnership
considers temporary investments with a maturity at the date of acquisition of 90
days or less to be cash equivalents. No cash was paid for interest or income
taxes for the three months ended March 31, 2005.

**Credit Risk**

Financial instruments, which potentially subject the Partnership
to concentrations of credit risk, consist principally of periodic temporary
investments of cash and cash equivalents. The Partnership places its temporary
cash investments in deposits with high-quality-financial institutions. At March
31, 2005, the Partnership had $2,552,500 in deposits at one bank of which
$2,452,500 was over the insurance limit of the Federal Deposit Insurance
Corporation. No losses have been experienced on such investments.

**Comprehensive Income**

The Partnership is
subject to the provisions of SFAS No.130, “Reporting Comprehensive Income,”
which requires disclosure of comprehensive income and its components.
Comprehensive income includes net income and all other changes in equity of a
business during a period from non-owner sources. These changes, other than net
income, are referred to as “other comprehensive income.” The Partnership has no
material elements of comprehensive income, other than net earnings, to
report.

**NOTE 3****-****TRANSACTIONS
WITH ATLAS RESOURCES, INC. AND ITS AFFILIATES**

The Partnership has entered into the following significant
transactions with Atlas Resources, Inc. (“Atlas”), the Managing General Partner,
and its affiliates as provided under the Partnership agreement:

·
    Administrative costs
      which are included in general and administrative costs in the Statements
      of Operations are payable to Atlas at $75 per well per month.
      Administrative costs incurred for the three months ended March 31, 2005
      and 2004 were $45,900 and $6,500,
respectively.

·
    Monthly
      well supervision fees which are included in production expenses in the
      Statements of Operations are payable to Atlas at $275 per well per month
      for operating and maintaining the wells. Well supervision fees incurred
      for the three months ended March 31, 2005 and 2004 were $165,200 and
      $19,400, respectively.

·
    Transportation
      fees which are included in production expenses in the Statements of
      Operations are payable to Atlas at $.29-$.35 per mcf (one thousand cubic
      feet). Transportation costs incurred for the three months ended March 31,
      2005 and 2004 were $162,400 and $28,300, respectively.

As managing general partner, Atlas performs all administrative and
management functions for the Partnership including billing revenues and paying
expenses. Accounts receivable - affiliate on the balance sheet represents the
net production revenues due from Atlas.9
Table of Contents
****
**ITEM 2. MANAGEMENT’S DISCUSSION AND
ANALYSIS AND RESULTS OF OPERATIONS (UNAUDITED)**

**Forward-Looking Statements**

WHEN USED IN THIS
FORM 10-QSB, THE WORDS “BELIEVES” “ANTICIPATES” “EXPECTS” AND SIMILAR
EXPRESSIONS ARE INTENDED TO IDENTIFY FORWARD-LOOKING STATEMENTS. SUCH STATEMENTS
ARE SUBJECT TO CERTAIN RISKS AND UNCERTAINTIES MORE PARTICULARLY DESCRIBED IN
ITEM 1 OF OUR ANNUAL REPORT ON FORM 10-KSB. THESE RISKS AND UNCERTAINTIES COULD
CAUSE ACTUAL RESULTS TO DIFFER MATERIALLY. READERS ARE CAUTIONED NOT TO PLACE
UNDUE RELIANCE ON THESE FORWARD-LOOKING STATEMENTS, WHICH SPEAK ONLY AS OF THE
DATE HEREOF. WE UNDERTAKE NO OBLIGATION TO PUBLICLY RELEASE THE RESULTS OF ANY
REVISIONS TO FORWARD-LOOKING STATEMENTS WHICH WE MAY MAKE TO REFLECT EVENTS OR
CIRCUMSTANCES AFTER THE DATE OF THIS FORM 10-QSB OR TO REFLECT THE OCCURRENCE OF
UNANTICIPATED EVENTS.

Management’s Discussion and Analysis should be read in conjunction
with our Financial Statements and the Notes to our Financial Statements.

**Results of Operations**

The following table
sets forth information relating to revenues recognized and costs and expenses
incurred, daily production volumes, average sales prices and production cost per
equivalent unit during the periods indicated:

**Three
      Months Ended**
    
    **Three
      Months Ended****March
      31,**
    
    **March
      31,****2005**
    
    **2004**Production
      revenues (in thousands)Gas
    
    $
    3,675
    
    $
    505Oil
    
    $
    158
    
    $
    2Production
      volumes:Gas (thousands of cubic feet
      (“mcf”)/day)
    
    
    5,674
    
    
    863Oil (barrels
      (“bbls”)/day)
    
    
    39
    
    
    1Average
      sales prices:Gas (per mcf)
    
    $
    7.20
    
    $
    6.43Oil (per bbl)
    
    $
    44.54
    
    $
    32.25Average
      production costs:As a percent of
    sales
    
    
    11
    %
    
    10
    %(per mcf equivalent
      unit)
    
    $
    .78
    
    $
    .65

10
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****
**ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS AND RESULTS OF
OPERATIONS (UNAUDITED) - (Continued)**

**Results of Operations - (Continued)**

**Revenues.**Our natural gas revenues were $3,674,800 and $505,200 for the three
months ended March 31, 2005 and 2004, respectively an increase of $3,169,600
(627%). This increase was partially due to an increase in production volumes to
5,674 mcf per day for the three months ended March 31, 2005, from 863 mcf per
day for the three months ended March 31, 2004, an increase of 4,811 mcf per day
(557%). The average sales price we received for our natural gas also increased
to $7.20 per mcf for the three months ended March 31, 2005 from $6.43 per mcf
for the three months ended March 31, 2004, an increase of $0.77 per mcf (12%).
The $3,169,600 increase in gas revenue for the three months ended March 31, 2005
as compared to the prior year similar period was attributable to a $2,778,400
increase in production volumes and a $391,200 increase in natural gas sale
prices. The overall increase in gas production volumes resulted primarily due to
all the wells being on line for the three months ended March 31, 2005.

**Expenses.** Production expenses
were $415,800 and $51,500 for the three months ended March 31, 2005 and 2004,
respectively, an increase of $364,300 (707%). This increase is primarily
attributable to an increase in operating, transportation and variable expenses
due to all wells being on line for the three months ended March 31, 2005.

Depletion and
depreciation of oil and gas properties as a percentage of oil and gas revenues
was 46% and 435% in the three months ended March 31, 2005 and 2004,
respectively. This percentage change is directly attributable to changes in
revenues and our oil and gas reserve quantities, product prices, production
volumes and changes in the depletable cost basis of oil and gas properties.

General and
administrative expenses for the three months ended March 31, 2005 and 2004 were
$56,800 and $17,100, respectively, an increase of $39,700 (232%). These expenses
include legal, tax and audit fees, as well as the monthly administrative fee
charged by the managing general partner. This increase is primarily due to
higher administrative fees as compared to the prior year similar period, due to
all wells being on line.

**Liquidity
and Capital Resources.** Cash proved by operating activities increased
$4,482,200 in the three months ended March 31, 2005 to $4,535,000 from $52,800
for the three months ended March 31, 2004. The increase was primarily due to an
increase in net earnings from operations before depletion and depreciation for
the current period, due to all wells being online for the three months ended
March 31, 2005, and decrease in accounts receivable.

Cash used in
financing activities increased $3,087,800 during the three months ended March
31, 2005 compared to the three months ended March 31, 2004. This increase is
directly related to distributions to our partners. The first distribution was
June 15, 2004.

We had no material
commitments to make capital expenditures and we do not expect any in the
foreseeable future, except that our managing general partner may withhold funds
for the future plugging and abandonment costs. Any additional funds, if
required, will be obtained from production revenues or borrowings from our
managing general partner or its affiliates, which are not contractually
committed to make loans to us. The amount that may be borrowed may not at any
time exceed 5% of our total subscriptions, and no borrowings will be obtained
from third parties.

11
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****
**ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS AND RESULTS
OF OPERATIONS (UNAUDITED) - (Continued)**

**Critical Accounting Policies**

The discussion and
analysis of our financial condition and results of operations are based upon our
financial statements, which have been prepared in accordance with accounting
principles generally accepted in the United States of America. The preparation
of these financial statements requires us to make estimates and judgments that
affect the reported amounts of our assets, liabilities, revenues and cost and
expenses, and related disclosure of contingent assets and liabilities. On an
on-going basis, we evaluate our estimates, including those related to provision
for possible losses, asset retirement obligations, depletion and certain accrued
liabilities. We base our estimates on historical experience and on various other
assumptions that we believe reasonable under the circumstances, the results of
which form the basis for making judgments about the carrying values of assets
and liabilities that are not readily apparent from other sources. Actual results
may differ from these estimates under different assumptions or conditions.

For a detailed
discussion on the application of our remaining policies critical to our business
operations and other accounting policies, see Note 2 of the "Notes to Financial
Statements" in our Annual Report on Form 10-KSB.

**Recently Issued Financial Accounting Standards**

In April 2005, the Financial Accounting Standards Board (“FASB”)
issued FASB Interpretation No. 47, Accounting for Conditional Assets Retirement
Obligations (“FIN 47”), which will result in (a) more consistent recognition of
liabilities relating to asset retirement obligations, (b) more information about
expected future cash outflows associated with those obligations, and (c) more
information about investments in long-lived assets because additional asset
retirement cost will be recognized as part of the carrying amounts of the
assets. FIN 47 clarifies that the term conditional asset retirement obligation
as used in Statement of Financial Accounting Standards (“SFAS”) No. 143,
Accounting for Asset Retirement Obligations, refers to a legal obligation to
perform an asset retirement activity in which the timing and (or) method of
settlement are conditional on a future event that may or may not be within the
control of the entity. The obligation to perform the asset retirement activity
is unconditional even though uncertainty exists about the timing and (or) method
of settlement. Uncertainty about the timing and (or) method of settlement of a
conditional asset retirement obligation should be factored into the measurement
of the liability when sufficient information exists.

FIN 47 also clarifies when an entity would have sufficient
information to reasonably estimate the fair value of an asset retirement
obligation. FIN 47 is effective no later than the end of fiscal years ending
after December 15, 2005. Retrospective application of interim financial
information is permitted but is not required. Early adoption of this
interpretation is encouraged. As FIN 47 was recently issued, the Company has not
determined whether the interpretation will have a significant adverse effect on
its financial position or results of operations.

**ITEM 3. CONTROLS AND
PROCEDURES**

**Evaluation of Disclosure Controls and
Procedures**

Under the
supervision and with the participation of our managing general partner’s
management, including our managing general partner’s Chief Executive Officer and
Chief Financial Officer, our managing general partner has evaluated the
effectiveness of the design and operation of its disclosure controls and
procedures (as defined in the Exchange Act Rule 13a-14(c)) as of the end of the
period covered by this report and based on their evaluation, the chief Executive
Officer and Chief Financial Officer have concluded that these disclosure
controls and procedures are effective in all material respects, including those
to ensure that information required to be disclosed in reports filed or
submitted under the Securities Exchange Act in recorded, processed, summarized,
and reported, within the time periods specified in the SEC’s rules and forms,
and is accumulated and communicated to management, including our managing
general partner’s Chief Executive Officer and Chief Financial Officer, as
appropriate to allow for timely disclosure. There have been no significant
changes in our internal controls or in other factors that could significantly
affect controls in the first quarter and subsequent to the date of their
evaluation.

**PART
II.** **OTHER
INFORMATION**

**ITEM
6. Exhibits**

**EXHIBIT INDEX**


**Exhibit
      No.**
    
    **Description**31.1
    
    Certification Pursuant to Rule
      13a-14/15(d)-14.31.2
    
    Certification Pursuant to Rule
      13a-14/15(d)-14.32.1
    
    Certification Pursuant to 18 U.S.C. Section 1350, as
      Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of
      200232.2
    
    Certification Pursuant to 18 U.S.C. Section 1350, as
      Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of
      2002

12
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****
**SIGNATURES**


Pursuant to the requirements of the Securities Exchange Act of
1934, the registrant has duly caused this report to be signed on its behalf by
the undersigned, thereunto duly authorized.


Atlas America Public #12-2003 Limited Partnership

By:
      (Signature and Title):
    Atlas
      Resources, Inc., Managing General Partner


By
      (Signature and Title):
    /s/
      Freddie M. KotekFreddie
      M. Kotek, Chairman of the Board of Directors,Chief
      Executive Officer and President


Date: May 16, 2005


In accordance with the Exchange Act, this report has been signed
by the following persons on behalf of the registrant and in the capacities and
on the dates indicated.


By
      (Signature and Title):
    /s/
      Freddie M. KotekFreddie
      M. Kotek, Chairman of the Board of Directors,Chief
      Executive Officer and President


Date: May 16, 2005



By
      (Signature and Title):
    /s/
      Nancy J. McGurkNancy
      J. McGurk, Senior Vice President,Chief
      Financial Officer and Chief Accounting
Officer


Date: May 16, 2005


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