A semiconductor device includes: a transistor having a first electrode coupled to a first power source node to which a first power source voltage is supplied, and a second electrode, and supplying a reference current to a temperature detection element; a diffused resistor including a first semiconductor region having a potential-fixing node coupled to the first power source node, and a second semiconductor region having a first resistor node coupled to the second electrode of the transistor and a second resistor node coupled to a second power source node to which a second power source voltage is supplied, and formed at a surface of the first semiconductor region; and a leakage current correction circuit for allowing a current having approximately the same magnitude and the same direction as a magnitude and a direction of a current flowing via the potential-fixing node and the second resistor node, to flow not via the diffused resistor but via the transistor.