To provide a harmfulness elimination treatment apparatus for perfluoro compound type exhaust gas allowing treatment of a large gas quantity of exhaust gas at low cost.

An apparatus is for a harmfulness elimination treatment for perfluoro compound type exhaust gas comprising a perfluoro compound gas diluted with a diluent gas and comprises exhaust gas quantity reduction means 2 of separating the diluent gas from the perfluoro compound type exhaust gas to reduce the exhaust gas quantity and harmfulness elimination means 6 of eliminating the harmfulness of the perfluoro compound gas in the exhaust gas with the exhaust gas quantity reduced by the exhaust gas quantity reduction means 2. The exhaust gas quantity reduction means 2 uses adsorption containers 22A and 22B which cause the perfluoro compound gas to be adsorbed by an adsorbent so as to separate the diluent gas and thereby reduce the exhaust gas quantity of the exhaust gas. The configuration eliminates the need of increasing the treating capacity of the harmfulness elimination treatment apparatus and allows treatment of a large gas quantity of exhaust gas at low cost.