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Exhibit
12.1
 CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF
2002
  1.
    
    I have reviewed this annual report on Form 20-F of Siemens Aktiengesellschaft;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;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;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)) and internal control over financial reporting (as
defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the company and have:
 (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;(b)
    
    Designed such internal control over
financial reporting, or caused such
internal control over financial
reporting to be designed under our
supervision, to provide reasonable
assurance regarding the reliability of
financial reporting and the
preparation of financial statements
for external purposes in accordance
with generally accepted accounting
principles;(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(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
 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):
 (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(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.
 
  /s/ KLAUS KLEINFELDKlaus KleinfeldChief Executive Officer