A photodetector includes N photodetection pixels arranged one-dimensionally or two-dimensionally and each for generating a detection signal in response to incidence of light, and a single output terminal for outputting the detection signal generated in each of the N photodetection pixels. Each of the N photodetection pixels includes an avalanche photodiode operating in Geiger mode, and a quenching resistor connected in series to the avalanche photodiode, and the N photodetection pixels are configured to output detection signals having time waveforms different from each other.