To provide a remote controller for which a battery is easily exchanged while keeping waterproofness, and which incorporates a duplicate key to prevent a lockout even when the battery is consumed.

A remote locking/unlocking device includes: an inner case 1 for which electric parts of a remote control locking/unlocking device are mounted on one surface and a storage part for the duplicate key of a cylinder lock is formed on the other surface to be a back surface of the one surface; and first and second shells 27 and 31 which are formed in a shallow box shape by thinning the inner surfaces respectively, and whose opening end edge is molded so as to be bonded to the outer side of the inner case. The inner case 1 is held between the first and second shells, and in the form of making the inner surface of the first shell face one surface of the inner case and making the inner surface of the second shell face the other surface of the inner case respectively, the first and second shells are integrally and detachably bonded to the inner case.