Switching circuit and power converter

Provided is a technique capable of suppressing oscillation noise of a semiconductor device and suppressing Miller noise. The present invention is provided with: a switching device for turning on or off a state between a drain terminal and a source terminal on the basis of a voltage applied between the gate terminal and the source terminal; a drive circuit which is provided with a first switching element and a second switching element, opens and closes the first and second switching elements according to a predetermined control signal, and outputs a drive voltage for driving the switching device to the gate terminal via an output terminal; a clamp circuit having a third switching element that conducts between a reference potential of the drive circuit and a connection point on a path connecting an output terminal of the drive circuit and a gate terminal, on the basis of a comparison result between a threshold potential generated on the basis of the reference potential of the drive circuit and the connection po