A production method for a hard disk board 10. The production method: makes it possible to achieve high-precision polishing by quickly selecting to change polishing conditions or replace a polishing pad on the basis of the flatness of the hard disk board 10; and suppresses the occurrence of defects in the hard disk board 10. The production method includes: a polishing step (S21) in which the hard disk board 10 is polished; a polished flatness measurement step (S24) in which the polished flatness of the hard disk board is measured; a polished flatness determination step (S41) in which the trend in the polished flatness of the hard disk board is calculated from the results of the measurement, and it is determined whether the trend in the polished flatness meets a 1A standard; and a polishing adjustment step (S25) in which, on condition that the trend in the polished flatness does not meet the 1A standard, it is determined (S42) whether changing the polishing conditions of the polishing step would make the trend in the polished flatness meet a 1C standard, and, on the basis of the results of the determination of whether the 1C standard would be met, the polishing conditions are changed (S43) or a polishing pad is replaced (S44).