Provided is an internal combustion engine for improving fuel-economy performance in any of the case where supercharging performed by an electric supercharger is required and the case where the supercharging is not required. The internal combustion engine includes: an electric supercharger; a supercharger; an electric motor; and a controller, the electric supercharger being for compressing an intake air by rotation of the supercharger caused with rotation of the exhaust turbine by an exhaust gas energy to perform supercharging and for rotationally driving the supercharger with electric-motor assistance by the electric motor; an exhaust bypass passage provided to bypass the exhaust turbine; and an opening and closing the exhaust bypass passage unit. In the internal combustion engine, the opening and closing the exhaust bypass passage unit opens the exhaust bypass passage until the supercharging is started by the electric supercharger.