A motor is provided with: a ring-shaped yoke having a shaft line as the center, a stator having a first tooth and a second tooth provided extending from the yoke to the inner circumference side or theouter circumference side, and a rotor which is a rotor that can rotate with said shaft line as the center, said rotor having a permanent magnet on the surface opposing the stator. The first tooth andthe second tooth both have a tip part opposing the permanent magnet. The permanent magnet has: a first magnetic pole and a second magnetic pole adjacent in the circumferential direction with said shaft line as the center, and a groove formed at the between-pole part of the first magnetic pole and the second magnetic pole. A gap L1 of the circumferential direction of the tip part of the first tooth and the tip part of the second tooth, and a width L2 of the circumferential direction of the groove satisfy 1.00 < L2/L1 <=3.75.