An ECU 70 is provided to an engine 50 including a TCV 57 that changes a tumble flow generated inside a cylinder and being configured to be capable of securing a cooling of a cylinder block 51 and suppressing an occurrence of a cooling loss in a cylinder head 52. The ECU 70 includes a control unit that feedback-controls the TCV 57 based on a primary blow-off voltage Vi so that a flow velocity of air flowing along a surface on the cylinder head 52 side becomes greater than a flow velocity of air flowing along a surface on the piston 53 side in a case where a flow velocity of air flowing along a surface on one of the cylinder head 52 side and the piston 53 side becomes greater than a flow velocity of air flowing along a surface on another side in the cylinder.