A brushless motor includes an external stator where a magnetic circuit is electrically formed by winding electric wires around an iron core; a bus bar bundling the electric wires and forming an external input terminal; and an internal rotor formed by integrating a permanent magnet and rotatably supported through a bearing with respect to the external stator, wherein an insulation plate is held on one end of the external stator and attached thereto a magnetic pole sensor detecting a magnetic pole of the permanent magnet.