To provide a variable intake device for an internal combustion engine capable of performing proper supercharging of intake air in the whole operation region.

In this variable intake device for the internal combustion engine provided with a control means for switching to enable intake through a long intake passage 22 in a low speed region of the engine and through a short intake passage 23 in a high speed region of the engine by an opening and closing valve 23c, the control means controls the opening and closing valve 23c to a I position for closing the short intake passage 23 in the low speed region of the engine, a II position for reducing ventilation resistance while opening the short intake passage 23 in a high speed and high load region of the engine, and a III position for achieving the maximum reflection positive pressure while opening the short intake passage 23 in a high speed and low load region of the engine.