The demodulation circuit of the present invention is a demodulation circuit, connected with a plurality of light-receiving sections each for receiving an optical signal and converting the signal into a binary pulse signal, operable to select and demodulate a pulse signal out of pulse signals that are supplied from the light-receiving sections, respectively, the demodulation circuit including: a judgment and selection section for detecting timing with which High level and Low level of each of the pulse signals are switched and for selecting at least one pulse signal based on the timing; and a demodulation section for demodulating the pulse signal selected by the judgment and selection section. Consequently, the demodulation circuit easily selects and demodulates a signal whose jitter component is small out of a plurality of supplied signals.