Abstract: An optical receiver includes an optical device that receives input light and converts the input light to an electric signal; an equalizer that carries out waveform shaping on the electric signal; an amplifier that amplifies the electric signal; a discrimination part that discriminates data of the electric signal; an input optical power detecting part that detects input optical power of the input light; and a control part that makes an error rate in the electric signal with respect to the input optical power worse when the input optical power detected by the input optical power detecting part is equal to or less than a value corresponding to minimum receiver sensitivity.