Dimmer for incandescent lamps and motors to be operated via push button or sensor contact. When pressing the key button, the power raises and decreases again automatically and keeps this setting if the key button is detached. If the key button is touched shortly in the desired setting, the dimmer switches off and upon touching it once again in the last dimmer setting it switches on again. Also to be employed as light dimmer in the clock frequency of 5 - 9 seconds per rise and decline.