A wavelength converting apparatus that improves output performance of laser light subjected to wavelength conversion while improving the efficiency of laser light wavelength conversion. Wavelength converting apparatus (100) has: nonlinear optical crystal (110) converting wavelength of laser light propagating inside wavelength converting apparatus (100); right angle prism (130) deflecting laser light emanating from nonlinear optical crystal (110) and causing the laser light to be incident on nonlinear optical crystal (110) again, and to propagate in parallel and in opposite directions at a predetermined distance with respect to laser light before emanation from nonlinear optical crystal (110); and first dichroic mirror (120) separating laser light subjected to wavelength conversion inside nonlinear optical crystal (110) from the laser light before incidence on nonlinear optical crystal (110) for a second time.