To provide a reference position correcting method of a stacker crane in an automated warehouse system, capable of minimizing influence on ordinary work such as an inlet-outlet even if an inlet reference position correcting work is performed, and capable of minimizing the movement of the stacker crane required for correcting a reference position.

This reference position correcting method corrects the reference position of the stacker crane 15 using an optical distance measuring sensor 31 arranged in the stacker crane 15 and a reflector arranged on the ground for reflecting a laser beam of the distance measuring sensor, and includes a step of discriminating the necessity for correcting the reference position when operating the automated warehouse system, a step of discriminating the existence of specific work for completing operation by the stacker crane 15 in the vicinity of the reference position when recognizing a reference position correction as necessary, a step of correcting the reference position after finishing the specific work when the specific work exists, and a step of correcting the reference position after preset allowable setting time when the specific work does not exist.