PURPOSE: To achieve longevity of a device without mechanical operate contact by arranging a CCD sensor two-dimensional according to key arrangement, and by having the CCD sensor correspondent to each key enclosed with a partition frame and covered with a translucent material.

CONSTITUTION: A CCD sensor 1 is composed of a photodiode Di, an accumulation electrode Ci, and of a shift electrode SHi, and each or plurality of the sensor 1 is enclosed with a partition frame 2 correspondent to key arrangement, and is covered with a translucent material 3. When the translucent materials 3 on keys from 5 through 9 are covered with a finger, a signal electric charge accumulated in the electrode Ci is altered, and upon successive turning on of the shift electrode SHi, turning on of the keys from 5 through 9 is detected, and the key input is thus performed. There is no longer mechanical operate contact, and longevity of the device can be achieved.