A brushless motor includes a rotor in which permanent magnets are provided on an inner circumferential surface of a rotor core, and a stator in which teeth are provided on respective ends of stator cores around each of which a coil is wound. Each of the teeth is formed such that the distance between a facing surface which faces the permanent magnet and an inner circumferential surface of the permanent magnet is increased from the center of the tooth to the end thereof. Therefore, the rate of variation in magnetic resistance in response to variation in position of the rotor can be minimized, whereby cogging torque can be markedly reduced.