A switching control circuit includes: a feedback control part that turns on/off an output switch element so that an output voltage of a switching output circuit becomes to be a target value; a synchronous control part that turns on/off a synchronous rectification element; and a reverse current detection part that detects a reverse current during a turning-on period of the synchronous rectification element, wherein the synchronous control part has operation modes including: an asynchronous mode in which the synchronous rectification element is always turned off; and a synchronous mode in which the synchronous rectification element is turned on when the output switch element is turned off, and is turned off when the reverse current reaches a predetermined reverse current detection level, and wherein the reverse current detection level is gradually raised when the synchronous control part is switched from the asynchronous mode to the synchronous mode.