To maintain the temperature of exhaust gas supplied to a catalyst within a catalyst activating temperature range.

In this engine exhaust gas temperature control device, the catalyst 18 converting at least one component of NOx, HC and CO contained in exhaust gas from the engine 11 is disposed in the exhaust passage 15 of the engine 11. The engine exhaust gas temperature control device includes: an exclusive cylinder 12a provided in the engine 11 and having an intake port connected to the exhaust passage 15 downstream of the catalyst 18 and an exhaust port connected to the exhaust passage 15 upstream of the catalyst 18; and a control means 28 controlling the intake valve 26 and exhaust valve 27 of the exclusive cylinder 12a for opening/closing in order to regulate temperature of exhaust gas delivered from the exhaust port of the exclusive cylinder 12a and supplied to the catalyst 18.