A coffee machine includes: a filter holder suitable for containing at least one coffee dose; a dispensing unit with dispensing nozzles suitable for sending a flow of hot water on the coffee dose; a water system provided with a pump to supply pressurized water towards the dispensing nozzles; a heater to heat the water to be supplied to the dispensing nozzles; a dispensing valve to enable/disable the supply of hot water towards the dispensing nozzles; a pre-infusion valve installed upstream the dispensing valve; and a control unit comprising actuation means to actuate the pre-infusion valve. The pre-infusion valve is a two-way electrovalve of programmable proportional type.