To surely check whether the extended amount of a slide fork corresponds to the size of an article by detecting the kind of the article, and eliminate wiring from a top part of the slide fork to a base part.

A projection member projecting freely in a height direction, and a detected member whose position changes by the projection of the projection member are provided at a top part of a slide fork of a stacker crane. A sensor for detecting a position of the detected member is provided at the base part, so as to detect a difference of a bottom shape of the article.