To provide an optically reconfigurable logic circuit in which a mount area of an optical circuit is reduced as much as possible and a high gate density is realized.In an optically reconfigurable logic circuit 1 provided with a plurality of configuration information input circuits 6 for converting an optical signal including logic circuit configuration information into an electric signal and holding and outputting this electric signal and a logic configuration variable circuit 7 for performing logic configuration on the basis of the logic circuit configuration information, the configuration information input circuits 6 holds the logic circuit configuration information as electric charge with use of a junction capacitance and a floating capacitance of a photoconductive device P. An inter-terminal voltage of the photoconductive device P is converted into binary data by a binary circuit and output as a circuit configuration signal. Then, the logic configuration variable circuit 7 is configured to execute a logic arithmetic processing before the inter-terminal voltage of the photoconductive device P drops to be equal to or lower than a logic threshold of the binary circuit due to a leak current.