To provide a synchronous machine provided with a magnetic pole position detector wherein degradation in performance due to temperature fluctuation in the output of a magnetoelectric device incorporated in a synchronous machine can be reduced using a simple constitution.

The synchronous machine is shifted to the phase delay side due to a temperature rise in a permanent magnet in the magnetic pole position detector. The magnetic pole position detector 2 outputs pulse voltage which is shifted to the leading phase side at electrical angles of 3 to 7°, more preferably 4 to 6° from the edge of the pulse voltage at maximum torque at an ordinary temperature (25°C). Thus, reduction in torque due to temperature fluctuation can be reduced very simply.