In an injection compression molding method, dies are clamped with low pressure and a melted thermoplastic resin composition is filled in a cavity space from a gate while moving the cavity space relative to the gate, and then the dies are clamped with a high pressure substantially simultaneously with completion of the filling to compress and form the thermoplastic resin composition filled in the cavity space. Since the thermoplastic resin composition containing a high content of thermally-conductive filler such as an electrically-conductive filler can be injected and compressed to be molded, the injection compression molding method can be applied in manufacturing molding such as a fuel cell separator and a flat antenna.