To improve laser efficiency in a laser device capable of emitting lights of a first wavelength and a second wavelength without causing high costs.

A flash lamp 52 irradiates a laser rod 51 with excitation light. A optical resonator includes a pair of mirrors 53 and 54 that face with each other with the laser rod 51 interposed therebetween. A wavelength switching unit 56 includes a long pass filter that transmits light of a first wavelength or longer. When a wavelength of laser light to be emitted is the first wavelength, the wavelength switching unit 56 inserts the long path filter on a light pass of the optical resonator.