A gripping jig for assembling whereby a force is applied to a molded body in a direction perpendicular to an assembling direction. When an assembling load is applied to the molded body, the force is adjustable with an adjustment screw such that the molded body is guided to move in the assembling direction. Since the force is applied from a direction different from the assembling direction, the molded body can move in the assembling direction, and since the force is adjustable, application of the assembling load to the molded body and the movement of the molded body can be adjusted. Since a plurality of the molded bodies are fixed and assembled respectively, when there are variations in size of the molded bodies, an excessive assembling load is is avoided with each molded body guided to move, so that a more uniform assembling load is applied to the plurality of molded bodies.