A motor comprising: a rotary shaft; a rotor including a hole in which the rotary shaft is disposed; a stator disposed at the outside of the rotor; and a cable assembly body connected to a coil of the stator, wherein the cable assembly body includes a connector, a plurality of cables including a connection terminal connected to the connector, and a rear holder for a cable of a motor coupled to a back surface of the connector, the rear holder comprising: a first body including a first groove, the first groove passing through a front surface and a back surface (1110C, 1510C) of the first body along a longitudinal direction; a second body including a second groove, the second groove passing through a front surface and a back surface of the second body along a longitudinal direction; and a coupling portion configured to couple the first body and the second body so that the first groove and the second groove are aligned to form a cable hole, wherein the first groove and the second groove include two protruding ribs therein, wherein the ribs protrude from the surface of the first groove and the second groove, wherein the ribs are disposed along a width direction perpendicular to the longitudinal direction of the first groove, one rib being disposed adjacent to an inlet of the first groove and one rib being adjacent to an outlet of the first groove, wherein each rib includes an area having a thickness in the width direction of the first groove and the second groove variable on the basis of a longitudinal direction of the first groove and the second groove, the thickness being formed to increase from the inlet to the outlet, wherein an upper surface of the ribs which comes in contact with the cable is a flat surface, a side surface of the rib being a curved surface, and wherein the plurality of cables include a first cable including an electromagnetic wave shield layer and a plurality of second cables not including the electromagnetic wave shield layer. a rotary shaft; a rotor including a hole in which the rotary shaft is disposed; a stator disposed at the outside of the rotor; and a cable assembly body connected to a coil of the stator, wherein the cable assembly body includes a connector, a plurality of cables including a connection terminal connected to the connector, and a rear holder for a cable of a motor coupled to a back surface of the connector, the rear holder comprising: a first body including a first groove, the first groove passing through a front surface and a back surface (1110C, 1510C) of the first body along a longitudinal direction; a second body including a second groove, the second groove passing through a front surface and a back surface of the second body along a longitudinal direction; and a coupling portion configured to couple the first body and the second body so that the first groove and the second groove are aligned to form a cable hole, wherein the first groove and the second groove include two protruding ribs therein, wherein the ribs protrude from the surface of the first groove and the second groove, wherein the ribs are disposed along a width direction perpendicular to the longitudinal direction of the first groove, one rib being disposed adjacent to an inlet of the first groove and one rib being adjacent to an outlet of the first groove, wherein each rib includes an area having a thickness in the width direction of the first groove and the second groove variable on the basis of a longitudinal direction of the first groove and the second groove, the thickness being formed to increase from the inlet to the outlet, wherein an upper surface of the ribs which comes in contact with the cable is a flat surface, a side surface of the rib being a curved surface, and wherein the plurality of cables include a first cable including an electromagnetic wave shield layer and a plurality of second cables not including the electromagnetic wave shield layer. a first body including a first groove, the first groove passing through a front surface and a back surface (1110C, 1510C) of the first body along a longitudinal direction; a second body including a second groove, the second groove passing through a front surface and a back surface of the second body along a longitudinal direction; and a coupling portion configured to couple the first body and the second body so that the first groove and the second groove are aligned to form a cable hole, wherein the first groove and the second groove include two protruding ribs therein, wherein the ribs protrude from the surface of the first groove and the second groove, wherein the ribs are disposed along a width direction perpendicular to the longitudinal direction of the first groove, one rib being disposed adjacent to an inlet of the first groove and one rib being adjacent to an outlet of the first groove, wherein each rib includes an area having a thickness in the width direction of the first groove and the second groove variable on the basis of a longitudinal direction of the first groove and the second groove, the thickness being formed to increase from the inlet to the outlet, wherein an upper surface of the ribs which comes in contact with the cable is a flat surface, a side surface of the rib being a curved surface, and wherein the plurality of cables include a first cable including an electromagnetic wave shield layer and a plurality of second cables not including the electromagnetic wave shield layer.