Provided is a random number generator including a single-photon emitter configured to emit single photons by pumping, a waveguide configured to guide the single photons emitted from the single-photon emitter to the inside of the waveguide, the waveguide including a first output terminal and a second output terminal that are respectively provided at both end portions of the waveguide, the single photons being output from the first output terminal and the second output terminal, and a first single-photon detector and a second single-photon detector respectively provided at the first output terminal and the second output terminal and configured to detect the single photons output from the first output terminal and the second output terminal, respectively.