In a brushless motor having a rotor in which a drive magnet 43 and a position detection magnet 44 are fixed to the inside of a rotor case 44, along the axial direction, an annular separation plate 45 having positioning parts 45a and 45b for positioning these in the circumferential direction is disposed between the drive magnet 43 and the position detection magnet 44. Thereby, the magnetic influence of the drive magnet can be limited, and thus a highly reliable position detection signal can be obtained.