A stem slide apparatus comprises a stem slide base (73) with a stem (6) horizontally mounted thereon to press a billet (B) mounted on a container (5), a slide guide member (72, 72a, 72b) mounted on a vertical stem move support member (71) and formed with guide grooves in which the side end portions of the stem slide base are fitted and vertically slid, and a lock means (77a, 77b) arranged on the slide guide member to press the side end portions of the stem slide base. The stem slide apparatus further comprises a drive mechanism (10) having an electric motor (11) to move the slide base in the sliding direction. Therefore the indirect cause of a fire is removed and the maintenance work simplified.