A class-D amplifier includes: an operational amplifier and capacitors, which constitute an integrator for integrating a difference between a plus-sided input signal and a minus-sided input signal which constitute analog input signals; delay circuits for delaying a phase of a triangular wave by a desirable very small angle; resistors, which constitute a synthesizing circuit for synthesizing an output of the integrator, the triangular wave, and outputs of the delay circuits with each other; comparators for comparing outputs of the synthesizing circuit with each other; AND circuits which constitute a buffer for inputting outputs of the comparators; and resistors feeding back an output of the buffer to an input side of the integrator.