The present invention relates to a loading device of a stacker crane. The present invention comprises: a first stage fork provided to slide to one side of a main frame in an access direction of a product; a first stage rack gear provided to one side of the first stage fork; a first stage pinion gear driving the first stage rack gear; a fork driving motor driving the first stage pinion gear; a second stage fork provided to slide with respect to the first stage fork in the access direction of the products; a second stage driven rack gear provided to one side of the second stage fork; a second stage pinion gear driving the second stage rack gear; and a second stage driving rack gear engaged with the second stage pinion gear. The present invention accesses a side surface of the product to enable the product to be stocked and released in order to minimize a loading height.
