PURPOSE: To increase the strength to a large extent by fixing sufficiently by pressure corrugated sections of a plate-shaped catalyst at the time of molding the plate-shaped catalyst.

CONSTITUTION: A molding device consists of plane sections 1 of a top force, a plurality of corrugated faces 2 of the top force, independent mechanically from the plane sections 1 of the top force and movable, springs 3 supporting in a manner of protruding the corrugated faces 2 of the top force from the plane sections 1 of the top force, a bottom force 4 with corrugated faces and plane faces corresponding to the corrugated faces and the plane faces of the top force and a driving device for making the top force close to the bottom force 4. As the corrugated faces of the top force and the corrugated faces of the bottom force are close together face to face sufficiently to the corrugated sections of a plate-shaped body by the above arrangement, the effect of increasing the strength of the plate-shaped body is provided.