To provide a method for keeping an edible part raw and yet capable of more efficiently separating the edible part from shells than conventional ones.

This method comprises momentarily heating the areas on the outer surface, corresponding to connecting positions of an adductor 3 and a trabecula 4, of the 1st shell 2A of a bivalve 1 in a shell closed state, forcibly opening both shells 2A and 2B in the closed state yet, inserting a cutting device 17 to tear off the adductor 3 from the 1st shell 2A and to cut the trabecula 4 at the connecting position to the 1st shell 2A, momentarily heating the areas on the outer surface, corresponding to connecting positions of the adductor 3 and the trabecula 4, of the 2nd shell 2B of the bivalve 1 and, with the cutting device 17, tearing off the adductor 3 from the 2nd shell 2B and cutting the trabecula 4 at the connecting position to the 2nd shell 2B.