An in-wheel motor, comprising: a circular rim having an outer ring capable of coupling to a tire; a shaft connected to the rim through a center of the rim; a motor assembly comprising a stator connected to the shaft in the rim and a rotor surrounding the stator to rotate about the stator; a cover coupled to an opening of the rim to block the motor assembly disposed inside the rim from an environment outside of the rim and having a center through which the shaft passes; and a bearing positionally constrained to an inside of the cover and supporting the shaft, wherein the shaft comprises: a first shaft body passing through the center of each of the rim and the cover and extending outward from the rim; and a second shaft body having a larger diameter than a diameter of the first shaft body, and wherein a power line for supplying power to the motor assembly is inserted into the second shaft body between the stator and the bearing in a radial direction and is extended in a longitudinal direction of the second shaft body, and wherein the second shaft body comprises: a first hole defined in the radial direction of the second shaft body in which the power line from the stator is inserted, and a second hole intersecting with the first hole and defined in the longitudinal direction of the second shaft body to take out the power line inserted through the first hole. a circular rim having an outer ring capable of coupling to a tire; a shaft connected to the rim through a center of the rim; a motor assembly comprising a stator connected to the shaft in the rim and a rotor surrounding the stator to rotate about the stator; a cover coupled to an opening of the rim to block the motor assembly disposed inside the rim from an environment outside of the rim and having a center through which the shaft passes; and a bearing positionally constrained to an inside of the cover and supporting the shaft, wherein the shaft comprises: a first shaft body passing through the center of each of the rim and the cover and extending outward from the rim; and a second shaft body having a larger diameter than a diameter of the first shaft body, and wherein a power line for supplying power to the motor assembly is inserted into the second shaft body between the stator and the bearing in a radial direction and is extended in a longitudinal direction of the second shaft body, and wherein the second shaft body comprises: a first hole defined in the radial direction of the second shaft body in which the power line from the stator is inserted, and a second hole intersecting with the first hole and defined in the longitudinal direction of the second shaft body to take out the power line inserted through the first hole. a first shaft body passing through the center of each of the rim and the cover and extending outward from the rim; and a second shaft body having a larger diameter than a diameter of the first shaft body, and wherein a power line for supplying power to the motor assembly is inserted into the second shaft body between the stator and the bearing in a radial direction and is extended in a longitudinal direction of the second shaft body, and wherein the second shaft body comprises: a first hole defined in the radial direction of the second shaft body in which the power line from the stator is inserted, and a second hole intersecting with the first hole and defined in the longitudinal direction of the second shaft body to take out the power line inserted through the first hole. a first hole defined in the radial direction of the second shaft body in which the power line from the stator is inserted, and a second hole intersecting with the first hole and defined in the longitudinal direction of the second shaft body to take out the power line inserted through the first hole.