A laser beam generating apparatus is configured such that a laser beam having a first wavelength obtained by a semiconductor laser containing gallium nitride is led in an external resonator using a nonlinear optical crystal. By allowing the laser beam to pass through the nonlinear optical crystal, an ultraviolet beam having a shorter wavelength is outputted as a laser beam. The wavelength of the ultraviolet beam becomes shorter by keeping the temperature of the nonlinear optical crystal at a low temperature. With this configuration, a laser beam in an ultraviolet region can be efficiently generated with a small apparatus.