PROBLEM TO BE SOLVED: To provide a gratin production method and a production device for gratin and soybean curd dough for gratin, capable of producing gratin which has a round shape or whose corners are chamfered, and whose corner parts are not minute, and having good and puffy texture.SOLUTION: A method for producing gratin which has a round shape or whose corners are chamfered comprises: a cut step for cutting a soybean curd dough 12 into size of a rectangular soybean curd dough 12 in consideration of vertical and lateral set elongation ratios due to bulking； a chamfering step for chamfering corner parts； and a step for performing bulking processing to the chamfered soybean curd dough 12 by a frying device at an actual elongation ratio equal to or less than the set elongation ratio. A production device 10 comprises a punching blade part 24 which has a punching blade 22 for punching a collection part of four corner parts of the adjacent rectangular soybean curd doughs 12 into a columnar shape, and which chamfers the corner parts of the cut rectangular soybean curd dough 12 or rectangular soybean curd dough 12 to be cut.
