A synchronous motor comprises: a stator wherein a concentrated winding is arranged to surround teeth (2b) in nine slots formed in a stator core (2); and a rotor disposed on the inner diameter side of the teeth (2b) and having ten-pole permanent magnets provided near the outer diameter side of a yoke core. The stator core (2) is configured such that the value of b divided by a is greater than 0.5, where a represents the width of a tooth tip portion (2c) provided on the inner diameterw side of a tooth (2b) from a root portion (2b1) between the tooth tip portion (2c) and the tooth (2b) to a circumferential end portion (2c1) of the tooth tip portion (2c), and b represents the thickness of the tooth tip portion (2c) from the root portion (2b1) to the inner diameter surface (2c2) of the tooth tip portion (2c).
