from the die when insufficient pressure is applied to the molten resin filling up the cavity the injection compression molding method of the present invention forms the compression allowances 80 the number of which being equal to that of the ejector pins as shown in fig6 and extrudes the molten resin of the compression allowances 80 into the cavity with the ejector pins to compress the molten resin filling up the cavity therefore shrinkage holes 93 as shown in fig5 b are not formed in the upper half case 90 on cooling and the upper half case 90 having a satisfactory appearance as shown in fig5 a can be produced pressure distribution in the cavities of injection molding dies in the pressure holding time was estimated by computer aided analysis fig7 shows pressure distribution in the cavity of an injection molding die in the pressure holding time in the injection molding cycle of a conventional injection compression molding method and fig8 shows pressure distribution in the cavity of an injection molding die in the pressure holding time in the injection molding cycle of the injection compression molding method of the present invention in which the pressure distribution is represented by isobaric.