To provide an optical receiver which can receive optical signals which are transmitted from various transmission sources and quickly change and steeply fall.

A time schedule stored in a time schedule storage part 16 and a reception intensity from each slave station 5 stored in a reception intensity storage part 17 are referred to preliminarily recognize at which time, from which slave station 5, and of which light intensity an incoming packet will be received. When an APD will receive an optical signal, a timing signal for setting a change timing of a bias voltage and a voltage value setting signal for setting a bias voltage value are given to a DC power source before reception of the optical signal, in order to supply the bias voltage most suitable for reception of the optical signal to the APD from the DC power source 12.