To enhance readiness of EGR control in a transitional period of reducing an EGR ratio required on intake air, in an internal combustion engine attached with a low pressure loop EGR device.

An internal combustion engine is formed as a structure for merging an intake passage 3 again before a cylinder 1 after branching the passage off once into a plurality of flow passages 3A and 3B in a downstream side area of a compressor 51 in the intake passage 3. Flow control valves 37A, 37B, 38A and 38B are arranged in an inlet part and an outlet part of the respective flow passages 3A and 3B, respectively. Intake air mutually different in EGR gas concentration can exist in the one flow passage 3A and the other flow passage 3B. In a transitional period of reducing a required EGR ratio of the intake air to be filled in the cylinder 1, an opening of an EGR valve 23 is fully closed or squeezed in a sufficiently small opening, and openings of the flow control valve 37B and the flow control valve 38B are adjusted, and thereby the EGR ratio of the intake air filled in the cylinder 1 is reduced.