To provide a space-saving variable intake device of an in-line four-cylinder internal combustion engine, capable of obtaining high intake air filling efficiency in the wide rotational speed range and having the small number of part items.

Ends of four independent intake passages 41 to 44 having the approximately equal length and the other ends to be communicated with and connected to respective cylinders are collected and communicated with and connected to a single intake collection chamber 3. A throttle valve 5 is provided in the upstream. A first communication port for communicating a pair of intake passages having each end to be communicated with and connected to respective cylinders in cylinder groups having intake strokes not to be continued and a second communication port for communicating a pair of intake passages having each end to be communicated with and connected to respective cylinders in the cylinder groups having intake strokes to be continued are alternately provided. Respective intake control valves are provided with valve shafts on the central parts of a collecting parts for the intake passages, closably arranged on the first and second communication ports, and individually opened or closed according to the rotational speed of the internal combustion engine, and the passages are communicated with or shut off from each other.