To enable a printed plastic sheet to be positioned and molded according to a shape of a molding by fixing a press having a hot plate and providing a molding box having a sheet holding part along an outer periphery which is movable with respect to the press.

A press 8 comprising a pressing cylinder 5 fixed by a column and a bracket, a hot plate 6, an air hole 7 or the like, and a molding box 9 having a molding are provided on a body so that they can be moved with a guide 10 as a guide on a water surface. Thus a vinyl chloride sheet 13 is attached to a plastic sheet attaching frame 12, the molding is fitted in the molding box 9, the hot plate 6 is lowered above it by the pressing cylinder 5, a small quantity of air is blown from below the box 9, and the plastic sheet 13 is brought into tight contact with the hot plate 6 for heating. The air in a lower part is exhausted, air is blown from the air hole 7 formed on the hot plate 6, and the plastic sheet 13 is brought into tight contact with the molding.