Abstract: A proximity detecting device for detecting the presence of an object in a target area. It comprises an emitter (1), a circuitry for supplying electrical pulses thereto, a receiver (3) arranged for receiving the emitted pulses and converting them into electrical signals, an amplifier for amplifying said electrical signals, and a control circuitry for determining on the basis of the amplified electrical signals whether or not the object is present in said target area. According to the invention it further comprises means for determining the amplitude of the amplified electrical signals and means for increasing the energy level of said electrical pulses when the amplitude of the amplified electrical signals is below a first threshold value and for decreasing the energy level of said electrical pulses when the amplitude of the amplified electrical signals is above a second threshold value, which is greater than or equal to said first threshold value.