To provide an analyzer which is constituted so as to measure the amounts of chlorine, sulfur and nitrogen in a sample, enables three analysises by one operation using one analyzing sample and can obtain high analytical precision.

The analyzer is constituted by successively arranging a sample gas supply mechanism (1), a chlorine analyzing mechanism (2), a sulfur analyzing mechanism (3), and a nitrogen analyzing mechanism (4). The sample gas supply mechanism (1) is equipped with a reaction tube (10), in which the sample is charged and to which oxygen is supplied, and a heating oven (13) and constituted so as to covert chlorine, sulfur and nitrogen in the sample to hydrogen chloride, sulfur dioxide and nitrogen monoxide to recover them as a sample gas. The chlorine analyzing mechanism (2) is equipped with a first titration cell (22) for performing the coulomb titration of hydrogen chloride in the sample gas and the sulfur analyzing mechanism (3) is equipped with an ultraviolet fluorescence detector (31) for measuring the fluorescence intensity of sulfur dioxide in the sample gas. The nitrogen analyzing mechanism (4) is equipped with an ozone generator (41) and a chemoluminescence detector (42) and chemoluminescence intensity is measured.