A thread cutting machine for cutting a thread by rotating a main spindle and moving a feed axis includes a main-spindle speed computing section that computes and outputs a rotation speed of the main spindle based on a main-spindle rotation speed instruction for each thread cutting pass, and an acceleration/deceleration time computing section that computes and outputs an acceleration/deceleration delay time of the feed axis for each thread cutting pass so that a product of multiplication of the acceleration/deceleration delay time of the feed axis and the rotation speed of the main spindle is the same for all thread cutting passes.