PURPOSE: To perform an analytical operation with high reliability by excluding the influence of a change or the like in an emission condition in an emission spectoscopic analytical apparatus.

CONSTITUTION: A voltage is applies across an electrode 2 and an object 3 to be measured, and light generated by an electric discharge is incident on a diffraction grating 5 via an entrance slit 4. Light which has been separated into its spectral components by the diffraction grating 5 is incident on a linear image sensor 6, the intensity of a spectral line is detected continuously with reference to a wavelength, and its detection signal is input to a microcomputer 11 as a digital signal via a data processing unit 7 and an interface board 8. The microcomputer 11 computes a background intensity Ib at the peak wavelength λ0 of the spectral line of a chemical element to be analyzed or the like, the background intensity Ib is removed from a spectral-line intensity Ip, and a real intensity Is is obtained. The concentration of the chemical element to be analyzed is computed on the basis of the actual intensity Is.