PROBLEM TO BE SOLVED: To provide a switching power supply capable of having resistance for switching noise and ensuring a sufficient phase margin while keeping operation in high frequency and excellent responsiveness.SOLUTION: A control circuit includes; a control part 5 connected to a switching element; a signal generation circuit 7 connected to an input part of the control part; a reference voltage source 8 connected to the signal generation circuit; a first input terminal Vo to which an output voltage of a switching power supply device is inputted; a second input terminal Vfb to which a comparison signal from the signal generation circuit is inputted; and a comparator 6 having an output terminal connected to the input part of the control part and the signal generation circuit.SELECTED DRAWING: Figure 1