In order to provide a gas chromatograph in which any adverse effects on a reduction reaction unit that are caused by the degradation of a reduction catalyst, and any adverse effects on an analyzing unit are prevented, a gas chromatograph is provided with: a column that, by causing a sample gas to pass through itself, is able to separate constituents for measurement that are contained in the sample gas; an oxidation reaction unit that uses an oxidizing gas to oxidize the sample gas that has passed through the column so as to create an oxidation sample gas; a reduction reaction unit that uses a reducing gas to reduce the oxidation sample gas created by the oxidation reaction unit so as to create an oxidation reduction sample gas; and an analyzing unit that analyzes the sample gas.
