According to an embodiment, an embedded magnet rotor comprises: a rotor shaft, a rotor core having permanent magnet housing spaces; and flat plate-shaped permanent magnets. Permanent magnet housing spaces each extend more radially outward than a position where the permanent magnet is held by a magnet holding outer projection and each have a communication opening communicating with a gap space. A radial thickness of each of the two chips sandwiching the communication opening and a circumferential width of the communication opening are in such a dimensional relation as to prevent a fragment produced by break of the permanent magnet from protruding from the communication opening and coming into contact with the stator.