In an intake device for an internal combustion engine, in which a valve body 11 rotatable about a valve shaft 12 is provided within an intake passage 3 and by which an intake flow is controlled, the valve shaft 12 is eccentric with a center of the valve body 11 and is supported at a position eccentric with a center of the intake passage 3. When the valve body 11 rotates, a half open state is formed from a fully closed state via a fully open state. The butterfly-type intake control valve are simply altered, so that the fully closed state, the fully open state, and the half open state can be formed and the vortex flow can be formed into the cylinder.