To take synchronization between subscriber's equipments by making operating timing of subscriber's equipments in matching with each other in the star optical subscriber system.

An intra-station equipment has a transmission delay time calculation section 19 between the intra-station equipment and each subscriber equipment, the transmission delay time is informed to each subscriber equipment by an outgoing direction signal from the intra-station equipment to each subscriber equipment and each subscriber equipment extracts transmission delay time information in the outgoing direction signal to use a timing that is advanced from a predetermined tentative operating timing by the transmission delay time as a true operating timing so as to make the operating timing of each subscriber equipment in matching with each other.