PURPOSE: To provide a corrugation molding machine in which a prepreg sheet is not adhered to a heat corrugated roll in the case of molding a corrugation, the molding of the corrugation is smoothly executed, a desired wave plate is effectively obtained, and hence cleaning of a surface of the roll is not necessarily conducted by a labor hour after the corrugation is molded.

CONSTITUTION: The corrugation molding machine 1 is used in manufacturing steps of a plastic or a fiber-reinforced plastic honeycomb core, and comprises a pair of upper and lower heat corrugated rolls 5 disposed at an interval sufficient to pass a prepreg sheet 4 therebetween and rotatably driven while being heated therein. The surface of the roll 5 is formed substantially in a gear state formed continuously in parallel with axially linear uneven waveshape part 7, and executed with release processing A to provide mold releasability. The sheet 4 is corrugatedly molded on a wave plate 8 by the machine 1.