An electronic current limiter includes a power supply transformation circuit to transform an alternating-current power supply into a direct-current power supply, a current detection circuit to sense and detect a current from the input terminals of the power supply transformation circuit and a detection control circuit to turn on or off the power supply according to an output signal of the current detection circuit. Thus, when the load current of the lamp is increased to exceed a predetermined value, the power supply to the lamp is interrupted to turn off the lamp so as to prevent the lamp from being worn out due to an excessive load current.