A left infrared camera module includes a left infrared irradiation unit configured to emit infrared toward a left side region of a vehicle, a left infrared camera configured to acquire infrared image data indicative of a surrounding environment in the left side region of the vehicle, and a control unit configured to control an operation of the left infrared irradiation unit. The control unit is configured to change an intensity of the infrared to be emitted from the left infrared irradiation unit, in correspondence to a condition relating to a traveling state of the vehicle. The left infrared camera module configured as described above can detect the surrounding environment in the side region of the vehicle without causing an uncomfortable feeling to other vehicle, a pedestrian and the like.