A noise reduction circuit receives, as an input signal, a voltage difference between two different signals. The noise reduction circuit includes: an amplifier circuit for amplifying the two different signals; a voltage difference detection circuit for detecting a voltage difference between the two different signals amplified by the amplifier circuit; and an electric charge accumulation circuit section or a voltage adding circuit. The electric charge accumulation circuit section accumulates, a predetermined number of times, an electric charge corresponding to the voltage difference detected by the voltage difference detection circuit and combines the accumulated electric charges to output the resultant electric charge. The voltage adding circuit adds, a predetermined number of times, the voltage difference detected by the voltage difference detection circuit.