Disclosed is a spectrometer apparatus using a continuous wave laser and a photomultiplier tube. The spectrometer apparatus includes a continuous wave laser irradiating part to irradiate a continuous wave laser to introduced particles, a scattering light measuring part to measure a scattering light emitted from the particles due to the continuous wave laser, a triggering signal generator to generate a triggering signal if a measurement value of the scattering light measuring part is greater than a preset value or equal to the preset value, a pulse laser irradiating part to receive the triggering signal to irradiate a pulse laser to the particles, and a spectral analysis part to measure an emission light generated from the particles due to the pulse wave laser to analyze elements consisting of the particles.