Provided is a large-size injection molded article which is obtained by injection molding a composition containing a heat-meltable fluoropolymer. Specifically, provided is a large-size injection molded article, which can be molded at a lower injection pressure as compared with a conventional PFA and obtained by molding a composition superior in mold release characteristics from a metal mold. This large-size injection molded article is superior in, particularly, heat resistance and chemical resistance, as well as dimensional accuracy, for a substrate processing apparatus.Provided is an injection molded article, having a projection area in an injection direction of 1100 cm2 or more, obtained by injection molding a composition containing a heat-meltable fluoropolymer. It is a preferable aspect that the composition including a heat-meltable fluoropolymer is a composition containing a melt moldable tetrafluoroethylene/fluoroalkoxytrifluoroethylene copolymer having an MFR over 60 g/10 minutes.