Disclosed herein is an electronic parking brake including: a carrier fixed to a body of a vehicle; a caliper housing that is slidably installed in the carrier; a motor that is disposed at an outside of the caliper housing and generates a rotational force; a decelerator that amplifies the rotational force of the motor; and a conversion unit that converts a rotational force transmitted from the decelerator into a rectilinear motion, wherein the decelerator includes a belt planetary gear part, and the belt planetary gear part includes: a solar gear rotated by receiving the rotational force of the motor; a belt gear engaged with the solar gear; a transmission plate that is connected to the belt gear and has belt support parts for supporting the belt gear so that the belt gear is rotatable; and a ring gear that is engaged with an outer surface of the belt gear and fixed to the belt gear so as to rotate the transmission plate.