A stacker (10) for plate members includes a platform (15) on which plate members (20) are to be stacked and at least one pair of guides (11, 13) disposed at both sides of the platform (15) relative to a transferring direction of the plate members. Each of the guides (11, 13) has a ridge (12a, 14a) spirally formed on a rotational axial portion (12, 14) and a groove (12b, 14b) formed along the ridge (12a, 14a). The aforementioned at least one pair of guides (11, 13) are rotated with opposite edges of the plate member (20) engaged with the grooves (12b, 14b) of the guides (11, 13), to thereby move the plate member (20) toward the platform (15).