An operation input device comprising: an infrared irradiation unit configured to radiate infrared; a capturing unit configured to detect the infrared to capture an image; an image processing unit configured to detect a shape of an indication object from a captured image which is the image captured by the capturing unit; a determination unit configured to determine an operation by the indication object from the shape detected by the image processing unit; and a command unit configured to make a device to be operated perform a function corresponding to the operation determined by the determination unit, characterized in that the operation input device further comprises: a luminance calculating unit configured to calculate, in the captured image, a luminance difference between a luminance of a first area irradiated with the infrared by the infrared irradiation unit and a luminance of a second area arranged outside the first area; and an infrared control unit configured to adjust an irradiation intensity of the infrared to be radiated from the infrared irradiation unit so that the luminance difference calculated by the luminance calculating unit becomes a predetermined target value; and a storage unit configured to store first luminance used for detecting the shape by the image processing unit in the first area in the captured image when the irradiation intensity is adjusted by the infrared control unit, and each second luminance of the second area in the captured image, wherein the luminance calculating unit configured to obtain third luminance of a plurality of second areas in the captured image captured by the capturing unit, and when an absolute value of a difference between the third luminance corresponding to at least any of the plurality of second areas and the second luminance is equal to or greater than a predetermined value, the luminance calculating unit configured to calculate a luminance correction value based on the difference so as to correct the first luminance by the luminance correction value. an infrared irradiation unit configured to radiate infrared; a capturing unit configured to detect the infrared to capture an image; an image processing unit configured to detect a shape of an indication object from a captured image which is the image captured by the capturing unit; a determination unit configured to determine an operation by the indication object from the shape detected by the image processing unit; and a command unit configured to make a device to be operated perform a function corresponding to the operation determined by the determination unit, characterized in that the operation input device further comprises: a luminance calculating unit configured to calculate, in the captured image, a luminance difference between a luminance of a first area irradiated with the infrared by the infrared irradiation unit and a luminance of a second area arranged outside the first area; and an infrared control unit configured to adjust an irradiation intensity of the infrared to be radiated from the infrared irradiation unit so that the luminance difference calculated by the luminance calculating unit becomes a predetermined target value; and a luminance calculating unit configured to calculate, in the captured image, a luminance difference between a luminance of a first area irradiated with the infrared by the infrared irradiation unit and a luminance of a second area arranged outside the first area; and an infrared control unit configured to adjust an irradiation intensity of the infrared to be radiated from the infrared irradiation unit so that the luminance difference calculated by the luminance calculating unit becomes a predetermined target value; and a storage unit configured to store first luminance used for detecting the shape by the image processing unit in the first area in the captured image when the irradiation intensity is adjusted by the infrared control unit, and each second luminance of the second area in the captured image, wherein the luminance calculating unit configured to obtain third luminance of a plurality of second areas in the captured image captured by the capturing unit, and when an absolute value of a difference between the third luminance corresponding to at least any of the plurality of second areas and the second luminance is equal to or greater than a predetermined value, the luminance calculating unit configured to calculate a luminance correction value based on the difference so as to correct the first luminance by the luminance correction value.