Abstract: A spraying device for cleaning apparatus, plant protecting apparatus or the like including a hand tool connected via a conduit to a pressure and heat generator for providing a liquid or vaporous agent under high pressure. A switch lever is held in the on position during operation. The lever controls a switch, the activation of which causes a transmitter for electric or electromagnetic waves arranged in the hand tool to send a switch-on command to a receiver located near the pressure and heat generator. The receiver operates a switch for controlling the pressure and heat generator, whereby upon release of the hand tool, such as unintentionally in the case of a dangerous condition, the switch-on command of the transmitter is interrupted and the pressure and heat generator switched off.