To perform a material injection process in both of two processes while holding both cavities to a half opened state and to perform a compression process while shortening a cycle time at the same time without requiring any special movement of a mold unable to damage the molding result of a first component.

An article made of a plastic material having two components is injection/compression-molded by a stack mold type pressing machine. In this molding, the molding cavity (B) of a second component (14) is held to a partially opened position during the injection and compression of the first component (13) in a first molding cavity (A). Further, holding systems (16, 34 and 35) are provided to be connected at least to one of the first and second cavities (A and B).