Provided is a technology for solving the drawback such as chipping of a heat-insulating layer which is caused by the contact of a heat-insulating layer formed on a first mold with a second mold at the mold parting surface. A mold divided into two or more is provided in which a heat-insulating layer is formed on a substantially entire surface of an inner wall surface of the mold, and the heat-insulating layer does not exist on a mold parting surface. For example, the mold is provided with a first mold occupying a majority of a cavity and a second mold which forms at least a part of the cavity together with the first mold, in which the first mold is provided with a flange part, and a part of a surface of the flange part constitutes a part of the mold parting surface.