To provide a method for a formed elastomer article, which can improve dimension accuracy of a formed elastomer article having an undercut without using a special die.

Using a correcting die 20 having an outer shape for the final formed article of a boot 1, the boot 1 in which pitches in a bellows are stretched by releasing from a core die is inserted into the correcting die 20, whereby the pitches in the bellows are adjusted to those corresponding to the dimension of the final formed article. Then, the correcting die 20 into which the boot 1 is inserted is introduced into a heating furnace at 50-230°C, followed by heating for a predetermined time, and then the correcting die 20 is cooled.