After a main unit has captured an image of a subject, the main unit is detached from a support post fixedly mounted in a compartment of a vehicle through a mounting/dismounting mechanism, and stored in a storage case disposed in the compartment of the vehicle. The storage case, which can be closed by a lid, incorporates therein first and second thermal insulating members made of a thermal insulating material, and first and second damping members disposed respectively in the first and second thermal insulating members for absorbing vibrations from the vehicle.