Molding method and die

A molding method for molding a seal member onto a first flat surface of a base material having the first flat surface, an inclined portion continuous with the first flat surface, and a second flat surface continuous with the inclined portion and higher than the first flat surface, the method comprising:

• a first step of injecting a raw material for the seal member into a groove at a temperature where the raw material is not vulcanized, in a first mold including the groove into which the raw material is injected;
• and
• a second step of sandwiching the base material between the first mold in which the raw material is injected into the groove and a second mold, and molding the raw material onto the base material as the seal member at a temperature where the raw material is vulcanized,
• wherein the first mold includes a shape that creates a gap between the shape and the inclined portion of the base material when the first flat surface and the second flat surface of the base material are pressed in the second step, and a connecting groove connecting the groove and the shape, and
• the groove of the first mold is provided in the vicinity of the shape.