PURPOSE: To provide the LED turning-on method with satisfactory turning-on confirmability by sufficiently securing and improving the luminance of LEDs even when the number of groups is increased after dividing the plural LEDs into groups in the case of turning on the LED by a function key fitted the LED among a lot of keys arranged on a keyboard.

CONSTITUTION: Concerning the LED turning-on method provided with a lot of keys fitted LEDs 3 so as to turn on the LEDs while repeatedly turning on and off the LEDs at these many keys in a certain prescribed cycle, the plural LEDs 3 are divided into several groups and based on lamp data to instruct the presence/absence of the turn-on processing for each group, the turn-on processing is executed only concerning the group having the lamp data to instruct the turning-on.