The present invention is to provide an electric wire protective cap. The protective cap can be formed easily by a resin molding and prevents a seal material from leaking and improves waterproof. The protective cap includes a cap main body with a bottom, and a cover to be fitted to the cap main body and having a hole to insert electric wires. A joint portion of the electric wires is inserted into the cap main body and locked or fixed by the cover. The cover has a locking portion for the joint portion and a locking portion for the cap main body. The cover is an elastic packing material. An outer wall of the cover contacts firmly with an inner wall of the cap main body. The electric wires contact firmly with the hole of the cover. An abutting portion is disposed in the cap main body to prevent the cover from being pulled out. The cover is formed from a disk plate by making a cutout in the hole and overlapping end surfaces of the cutout.