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Exhibit 12.1

CERTIFICATION OF CHIEF EXECUTIVE
OFFICER PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Heinrich v. Pierer, certify that:



|1. |  | I have reviewed this annual report on Form 20-F of Siemens
Aktiengesellschaft;
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|2. |  | Based on my knowledge, this report does not contain any untrue statement
of a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements
were made, not misleading with respect to the period covered by this
report;
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|3. |  | Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows of
the company as of, and for, the periods presented in this report;
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|4. |  | The companys other certifying officer(s) and I are responsible for
establishing and maintaining disclosure controls and procedures (as
defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the company and
have:
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| | (a) |  | Designed such disclosure controls and procedures, or
caused such disclosure controls and procedures to be designed
under our supervision, to ensure that material information
relating to the company, including its consolidated subsidiaries,
is made known to us by others within those entities, particularly
during the period in which this report is being prepared;
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| | (b) |  | Reserved;
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| | (c) |  | Evaluated the effectiveness of the companys disclosure
controls and procedures and presented in this report our
conclusions about the
effectiveness of the disclosure controls and procedures, as of the
end of the period covered by this report based on such evaluation;
and
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| | (d) |  | Disclosed in this report any change in the companys
internal control over financial reporting that occurred during
the period covered by the annual report that has materially
affected, or is reasonably likely to materially affect, the
companys internal control over financial reporting; and
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|5. |  | The companys other certifying officer(s) and I have disclosed, based on
our most recent evaluation of internal control over financial reporting,
to the companys auditors and the audit committee of the companys board
of directors (or persons performing the equivalent functions):
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| | (a) |  | All significant deficiencies and material weaknesses in
the design or operation of internal control over financial
reporting which are reasonably likely to adversely affect the
companys ability to record, process, summarize and report
financial information; and
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| | (b) |  | Any fraud, whether or not material, that involves
management or other employees who have a significant role in the
companys internal control over financial reporting.
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Date: December 5, 2003

/s/ HEINRICH v. PIERERHeinrich v. Pierer
Chief Executive Officer