Abstract: A reference voltage generating circuit generates a reference voltage having a flat temperature characteristic over a practical temperature range. In a reference voltage transistor pair, a depletion N-channel field effect transistor and an enhancement N-channel field effect transistor are connected in series between a first voltage source and a second voltage source so that the reference voltage is output from a juncture between a gate of the depletion N-channel field effect transistor and a gate of the enhancement N-channel field effect transistor. A temperature characteristic correction circuit is provided to at least one of the depletion N-channel field effect transistor and the enhancement N-channel field effect transistor. The temperature characteristic correction circuit changes temperature sensitivity of the reference voltage by changing an effective gate size of the one of the depletion N-channel field effect transistor and the enhancement N-channel field effect transistor.