A method for producing an injection-molded product includes steps of placing, in an injection mold, a heat-shrinkable resin sheet having region A and region B which have different surface temperatures when irradiated with infrared rays integrating the resin sheet with an injection molding resin by injecting the injection molding resin into the mold and, before the resin sheet is placed in the injection mold or before the integration step after the placing of the resin sheet in the injection mold, irradiating the resin sheet with infrared rays so that the surface temperatures of region A and region B are different from each other and the surface temperature of at least region A is equal to or higher than an orientation release stress inflection point temperature T of the resin sheet, thereby forming a difference in thickness between regions A and B.
