PURPOSE: To obtain higher analytic performance, by generating a high frequency of 40MHz band from a high frequency signal generator, providing said high frequency signal generator in a torch unit, increasing excitation efficiency of an atom in a sample further decreasing background light emission.

CONSTITUTION: A device 1 is equipped with a torch unit A and atomizer B, and a frequency of a high frequency current, fed by a high frequency oscillator C, is selected to a 40MHz band higher than a conventional frequency, then only in the vicinity of a plasma surface is heated by a skin effect, while plasma gas temperature itself is decreased, and intensity of background light emission is decreased, thus the detection limit of a desired signal is improved. If a frequency is increased, excitation efficiency of an atom in a sample is increased, and intensity of a desired light emission signal is increased, then a light emitting signal from each atom can be well caught, while introduction efficiency of power is increased by a change of the frequency, and power consumption can be reduced.