A semiconductor chip molding apparatus includes an upper platen including an upper mold, a lower platen including a lower mold having a molding block configured to receive a lead frame, a controller, and an electrical detector for forming an electrical circuit between the controller and the lead frame when the lead frame is oriented improperly on the lower mold. A low-level test voltage is imparted to at least the lower mold. As a result, an electrical signal will flow from the detecting block when the lead frame rests on the detecting block. When such a signal is detected, therefore, the lead frame is determined as having been improperly set on the molding block. The signal generated is detected by a controller and used thereby to interrupt the operation of the molding apparatus.