PURPOSE: To simply and easily change the unlocking number or a plurality or push buttons, in a push-button type lock for a bag.

CONSTITUTION: A slide plate 3 with fitting hole 32 to a fitting plate attached to the cover side of a bag and a plurality of lock shafts 7, 7 having two fan- shaped cams displaced 180 degrees and a fitting cone-shaped collars are position ed in the finder hole 12 of the slide plate. Elastic stoppers to which the fitting cone-shaped collars attach or from which they detach are arranged in a row in a lock shaft-fitting plate 4 separating a plurality of lock shafts into the upper and lower stages. A protrusion 33 where the fan-shaped cam of the lock shaft is fitted to the edge of the finder hole of the slide plate, is protruded as a unit.