A molding apparatus comprises first and second mold chases that are configured to clamp an electronic device therebetween, and a driving mechanism which drives the first and second mold chases to apply a clamping force onto the electronic device. A pressure adjustment mechanism communicates with at least one of the mold chases and applies an additional clamping pressure onto one or more portions of the mold chase. The pressure adjustment mechanism comprises movable supports that are displaceable in directions which are substantially perpendicular to the direction of the clamping force so as to transmit and apply the said additional clamping pressure onto the mold chase, and also a plurality of piezoelectric actuators which are operative to apply displacement forces to the movable supports in their displacement directions.