A temperature detecting circuit includes a first rectifying element with a cathode at a first reference voltage and an anode connected to a first node, a first impedance element connected in series with a second rectifying element between the first rectifying element and a second reference voltage, a third rectifying element with a cathode at the first reference voltage and an anode connected to a second node, a second impedance element and a fourth rectifying element connected in series between the third rectifying element and the second reference voltage, and a differential amplifier that outputs a differential signal pair corresponding to the difference in potential between the first node and the second node. The differential signals in the pair vary in magnitude in opposite directions in response to temperature changes.