<PAGE>
                                                                    EXHIBIT 31.2

                  CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER
            PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Larry C. Miller, certify that:

1. I have reviewed this quarterly report on Form 10-Q for the period ended
September 30, 2003 of Butler Manufacturing Company;

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 registrant as
of, and for, the periods presented in this report;

4. The registrant's other certifying officer 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 registrant and we 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 registrant, including its
consolidated subsidiaries, is made known to us by others within those entities,
particularly during the period in which this quarterly report is being prepared;

    b) evaluated the effectiveness of the registrant'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

    c) disclosed in this report any change in the registrant's internal control
over financial reporting that occurred during the registrant's most recent
fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual
report) that has materially affected, or is reasonably likely to materially
affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
registrant's auditors and the audit committee of the registrant's board of
directors (or persons performing the equivalent function):

    a) all significant deficiencies and material weaknesses in the design or
operation of internal controls over financial reporting which are reasonably
likely to adversely affect the registrant'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 registrant's internal controls over
financial reporting.



                  November 14, 2003      /s/ Larry C. Miller
                  -----------------      -------------------
                  Dated                  Larry C. Miller
                                         Vice President - Finance,
                                         and Chief Financial Officer