Coffee machine

In a coffee machine comprising a source of water (1) and an electric pump (6) to transfer water to a brewing chamber (3) after passing through a heat exchanger (7) where it is heated by an electric resistor (8) able to instantly bring the water to the desired reference temperature (Tr), at least one water delivery counter means (12) that instant by instant measures the quantity of water transferred towards said chamber, a temperature sensor (13) that instant by instant detects the temperature reached by the water and a single control device (14A) that receives signals from said temperature sensor (13) set in contact with the water duct (2) downstream and close to the heat exchanger (7), the control device (14 A) being programmed to control instant by instant the pump delivery (6,24) as a function of the signals received from the temperature sensor (13) and separately to control the electric feeding (8,15) of the heat exchanger (7) as a function of the signals received from the water delivery counter (12), the improvement wherein the control device (14 A) processes the signals received from the temperature sensor (13) to control simultaneously instant by instant the pump delivery (6,24) and the electricity feeding (8,15) of the heat exchanger (7) so as to maintain at the reference temperature (Tr) the water exiting the heat exchanger (7).