In a photon pair generating apparatus for generating a pair of correlated photons by hyper-parametric scattering, a light-shaping section irradiates an optical resonator with two beams of light of equal wavelength from different directions, and the optical resonator is configured to emit two correlated photons of different wavelengths in one direction as a pair of correlated photons. This makes it possible to provide a photon pair generating apparatus capable of achieving generation of a pair of correlated photons by a simpler configuration.