The present invention aims to provide a method for making disposable diapers so improved that no displacement of the absorbent core from the middle between a pair of the leg elastic members. The method includes the step P1 of bonding under tension elastic members to webs continuously fed in a machine direction MD to form front and rear sheet members 20, 30, the step P2 of bonding an absorbent panel 4 provided along opposite long sides of a rectangle with a pair of elastic members 42 for a crotch region and including an absorbent core 5 bonded thereto so as to be symmetric about an imaginary center line bisecting a distance between a pair of the elastic members for the crotch region to the front and rear sheet members at regular intervals and the step P3 of cutting the front and rear sheet members.