An electrically insulated switching element driver includes: a pulse transformer driving unit into which a switching element driving signal and a duty signal are input and which drives, in accordance with the duty signal, a first or second pulse transformer that is selected depending on a state of the switching element driving signal; a first edge detection unit that outputs an on-off signal according to an edge in a pre-rectification output of the first pulse transformer; a second edge detection unit that outputs an on-off signal according to an edge in a pre-rectification output of the second pulse transformer; and a control driving unit that drives a switching element to be driven, based on the output of the first and second edge detection units, wherein the first and second edge detection units and the control driving unit operate with power resulting from rectifying the output of the first and second pulse transformers.