A motor comprising: a rotating shaft; a rotor comprising a rotor core and magnets arranged on an outer circumferential surface of the rotor core and a hole into which the rotating shaft is inserted; and a stator disposed outside the rotor, wherein the stator comprises: a stator core which comprises a plurality of teeth; and a coil wound on each of the plurality of teeth, wherein each of the plurality of teeth comprises a body, on which the coil is wound, and a shoe connected to the body, wherein the shoe comprises a plurality of semicircular grooves, the grooves being formed toward the rotating shaft, the grooves being arranged lengthwise along an axial direction from a top end to a bottom end of the stator core, the grooves having a semicylindrical shape, a lateral cross section of the grooves having a semicircular shape, wherein the shoe is arranged to face a magnet of the rotor, an air gap being formed between an inner surface of the shoe and an outer surface of the magnet, wherein the number of the grooves is two, and wherein the two grooves are arranged to be symmetrical to each other on the basis of a reference line which passes a center of a width of the shoe based on a circumferential direction and a center of the stator core, characterized in that a center of a lateral cross section of the groove is disposed to be spaced at a certain angle θ2 apart from one side end point of the shoe in a circumferential direction, on the basis of the center of the rotating shaft, wherein the angle θ2 is 0.45 to 0.55 of an angle θ1 formed by a slot opening being a space between an end point of the shoe and an end point of another shoe adjacent thereto, on the basis of the center of the rotating shaft, wherein the radius of the groove is 0.9 to 1.1 of a distance of the air gap between the inner surface of the shoe and the outer surface of the magnet at the center of the width of the magnet. a rotating shaft; a rotor comprising a rotor core and magnets arranged on an outer circumferential surface of the rotor core and a hole into which the rotating shaft is inserted; and a stator disposed outside the rotor, wherein the stator comprises: a stator core which comprises a plurality of teeth; and a coil wound on each of the plurality of teeth, a stator core which comprises a plurality of teeth; and a coil wound on each of the plurality of teeth, wherein each of the plurality of teeth comprises a body, on which the coil is wound, and a shoe connected to the body, wherein the shoe comprises a plurality of semicircular grooves, the grooves being formed toward the rotating shaft, the grooves being arranged lengthwise along an axial direction from a top end to a bottom end of the stator core, the grooves having a semicylindrical shape, a lateral cross section of the grooves having a semicircular shape, wherein the shoe is arranged to face a magnet of the rotor, an air gap being formed between an inner surface of the shoe and an outer surface of the magnet, wherein the number of the grooves is two, and wherein the two grooves are arranged to be symmetrical to each other on the basis of a reference line which passes a center of a width of the shoe based on a circumferential direction and a center of the stator core, characterized in that a center of a lateral cross section of the groove is disposed to be spaced at a certain angle θ2 apart from one side end point of the shoe in a circumferential direction, on the basis of the center of the rotating shaft, wherein the angle θ2 is 0.45 to 0.55 of an angle θ1 formed by a slot opening being a space between an end point of the shoe and an end point of another shoe adjacent thereto, on the basis of the center of the rotating shaft, wherein the radius of the groove is 0.9 to 1.1 of a distance of the air gap between the inner surface of the shoe and the outer surface of the magnet at the center of the width of the magnet.