A solid state laser device includes a seed laser that outputs continuous wave laser seed light, a light intensity changeable unit that changes a light intensity thereof and outputs seed pulse light, a CW excitation laser that outputs continuous wave excitation light, an amplifier that amplifies the seed pulse light and outputs amplified light based on an amplification gain increased by the excitation light, a wavelength conversion unit that converts a wavelength of the amplified light and outputs harmonic light, and a light intensity control unit that allows the light intensity changeable unit to output the seed pulse light after a certain time elapsed from an input of an external trigger signal each time the signal is input and output suppression light that suppresses an increase of the amplification gain in a period after an output of the seed pulse light until an input of a next external trigger signal.