The present invention provides rotor including: a rotor core having a cylindrical shape; and a plurality of magnets disposed to surround an outer circumferential surface of the rotor core, wherein the magnet includes an inner circumferential surface in contact with the outer circumferential surface of the rotor core, when a first angle is defined by dividing an angle formed by the outer circumferential surface of the rotor core by the number of magnets, a second angle is formed by a first extension line and a second extension line which extend from both end points of the inner circumferential surface of the magnet to a center point of the rotor core on cross sections of the rotor core and the magnet, and a ratio of the second angle to the first angle is in a range of 0.87 to 0.93, thereby providing an advantageous effect of greatly reducing a cogging torque by decreasing a width of the magnet to double a cogging main degree.