The present invention addresses the problem of providing a resin-molding die that allows clamping without exerting excessive stress on the workpiece, regardless of the existence and magnitude of variations in the thickness of the workpiece. As a means for solving the problem, the height of a workpiece support (37) is adjusted by a thickness-varying mechanism to match the thickness of a substrate (1), and the height of a cavity recess (32) is adjusted by a cavity-height-varying mechanism to match the height of a semiconductor chip (5) before molding resin is injected into the cavity.