Abstract: Provided is an electronic locking device having a variable security code number input unit. The security code number input unit includes two or more input sets, each of which input elements indicated by numbers, letters, or a combination thereof, and preferably some or all of the numbers from 1 to 9 or from 0 to 9, are fixedly arranged. When an input signal is applied, a microcontroller enables light sources for the input elements of all or some of the input sets to emit light such that a real input set is made up of numbers, letters, or a combination thereof, and preferably of a combination of some or all of the numbers from 1 to 9 or from 0 to 9. Thereby, it is possible to prevent the possibility of revealing the security code number, to minimize power consumption, and to ensure that the security code number is easy to input.