Provided is a brushless DC motor (2) including: a stator (5) around which windings are around; a magnet rotor (6) configured to rotate by a power supply to the stator; an inverter circuit (11) connected to the stator; a position detector (7) configured to detect a positional relationship between the magnet rotor and the windings; a speed instruction unit (13) configured to output, as a speed instruction signal, a voltage corresponding to a rotation speed of the magnet rotor; a duty determination unit (12) configured to determine a duty of a voltage applied to the stator, based on the speed instruction signal; a drive controller (14) configured to distribute and output a duty signal based on the positional relationship and the duty; and temperature-sensitive resistance elements (15) configured to, by increasing the resistance in response to a temperature rise, reduce the voltage given as the speed instruction signal.