An interior permanent magnet type brushless direct current (BLDC) motor includes a stator having a plurality of slots. The BLDC motor also includes a rotor positioned in the stator and that is rotatable with respect to the stator. The rotor has a rotor core, a plurality of permanent magnets inserted in the rotor core, a plurality of vent holes positioned between the center of the rotor core and the permanent magnets, and a plurality of coupling holes positioned between the permanent magnets and a periphery of the rotor core.