PURPOSE: To improve decoration effect by flashing plural light emitting diodes at a specified periodic cycle while changing brightness of them gradually by an adjusting circuit.

CONSTITUTION: Oscillation waveforms of rectangular waves are obtained at a connection point A of NOT circuits 7, 8 inside an oscillation circuit 3. Because a Zener diode having specified current characteristics is used inside a brightness adjusting circuit 4 at a point B of a plus terminal of a capacitor C1, waveforms of triangular waves plus the Zener diode characteristics are obtained. Brightness of light emitting diodes 2 connected to this circuit 4 are thus changed to become bright gradually, and then become dark gradually, while they flash at a periodic cycle determined by the circuit 3. By changing a constant R1 of a resistor inside the circuit 3, the periodic cycle of oscillation can be changed.