To improve an image quality and to save power by cooling a CCD imaging element in a short period of time and to maintain portability of a digital camera by detachably providing a cooling mechanism.

An image of a subject is focused in a CCD imaging element 12 via a lens unit 11. The element 12 is held on the holding surface of a CCD holder 13, and a temperature sensor 15 is provided on the contact surface 14 of the holder 13. Various parameters necessary to set the camera 1 are supplied from a camera parameter unit 17 in an arithmetic unit 16. A display of whether various setting of the camera, the temperature detected by the sensor 15 and the temperature of the element 12 are the temperature suitable for imaging or not is displayed on a display unit 18. The contact of an inserting unit 21 with the surface 14 is provided in an inserting path 19 when the unit 21 of a detachably cooling unit 2 is inserted.