APPARATUS HAVING PLURAL SWITCH KEYS

PROBLEM TO BE SOLVED: To facilitate key operation from the back side by providing a display showing the arrangement of plural switch keys on the back side corresponding to the arrangement position of plural switch keys arranged on the surface side. SOLUTION: An apparatus having plural switch keys, for example, a photodetector 1 used in survey has a surface side case 11 and a back side case 12. A photodetecting part 2, a display part 3a and switch keys 4 (4a, 4b, 4c, 4d) are arranged on the surface side case 11, a display part 3b is provided on the back side case 12, and displays 9 (9a, 9b, 9c, 9d) are arranged in positions corresponding to the switch keys 4. When the photodetecting part 2 detects a rotary irradiated light ray, it is necessary to conduct work at the back side not to be an obstacle. In such a case, even if the switches of the apparatus can not be seen, the operation can be performed by touch by the arrangement of the switch keys shown in the displays 9.