Provided herein is a charger with improved radiation function capable of lowering its surface temperature to prevent the surface temperature from increasing excessively, the charger according to one aspect of the present disclosure including a printed circuit board on which circuit elements are mounted; an inner case formed in a hollow case shape of which both surfaces are open, and where the printed circuit board is arranged inside; a radiation member formed to cover an outer surface of the inner case to release heat generated in the circuit elements of the printed circuit board; an outer case formed to encompass the radiation member and provided with one open surface; a cover assembled in the outer case and configured to close the one open surface of the outer case; and a terminal coupled to one surface of the outer case, and configured to enable electricity to be supplied to the charger when inserted into a consent.