A molding method and a mold for molding a plastic shutter, wherein a plate-like member with a free end is extended into a molding cavity to define an injection together with at least two opposed planar plates. A thrust member, which is movable in the direction of thickness of the plate-like member and which applies a thrust force to the plate-like member, is provided close to the free end of the plate-like member. In a state where the amount of movement of the thrust member is adjusted to within a predetermined range as viewed in the thickness direction of the plate-like member, on the basis of the position where the forward end of the thrust means comes in contact with the plate-like member, molten resin is injected into the injection space, thereby forming the plastic shutter.