A photodetector and a method of manufacturing the photodetector are provided, in which variation in sensitivity is suppressed over the near-infrared region from the short wavelength side including 1.3 μm to the long wavelength side. The photodetector includes, on an InP substrate, an absorption layer of a type II multiple quantum well structure comprising a repeated structure of a GaAsSb layer and an InGaAs layer, and has sensitivity in the near-infrared region including wavelengths of 1.3 μm and 2.0 μm. The ratio of the sensitivity at the wavelength of 1.3 μm to the sensitivity at the wavelength of 2.0 μm is not smaller than 0.5 but not larger than 1.6.