Coffee machine comprising: - a filter holder suitable for containing at least one coffee dose, - a dispensing unit suitable for receiving the filter holder; said dispensing unit being provided with dispensing nozzles suitable for sending a flow of hot water on the coffee dose contained in the filter holder, - a water system provided with a pump to supply pressurized water to said dispensing nozzles of the dispensing unit, - a heater disposed in said water system to heat the water to be supplied to the dispensing nozzles, - a dispensing valve disposed in said water system between the heater and the dispensing nozzles to enable/disable the supply of hot water to said dispensing nozzles, - a pre-infusion valve disposed in said water system upstream said dispensing valve, and - a control unit comprising actuation means to actuate said pre-infusion valve, wherein said pre-infusion valve is a two-way electrovalve of programmable proportional type, comprising a shutter suitable for gradually opening and closing the communication between the two ways of the valve proportionally to a command signal sent by said actuation means; characterized in that the actuation means and the pre-infusion valve are configured in such a way to have: - a dispensing time (Te) from the moment when the pre-infusion valve is opened to the moment when the pre-infusion valve is closed, - an opening time from the moment when the pre-infusion valve starts opening to the moment when the pre-infusion valve is completely open, - a maximum flow time in which the pre-infusion valve is completely open, and - a closing time from the moment when the pre-infusion valve starts closing to the moment when the pre-infusion valve is completely closed; wherein the opening time is higher than 1/3 of the dispensing time (Te), the maximum flow time is lower than 1/3 of the dispensing time (Te), and the closing time is higher than 1/3 of the dispensing time (Te). - a filter holder suitable for containing at least one coffee dose, - a dispensing unit suitable for receiving the filter holder; said dispensing unit being provided with dispensing nozzles suitable for sending a flow of hot water on the coffee dose contained in the filter holder, - a water system provided with a pump to supply pressurized water to said dispensing nozzles of the dispensing unit, - a heater disposed in said water system to heat the water to be supplied to the dispensing nozzles, - a dispensing valve disposed in said water system between the heater and the dispensing nozzles to enable/disable the supply of hot water to said dispensing nozzles, - a pre-infusion valve disposed in said water system upstream said dispensing valve, and - a control unit comprising actuation means to actuate said pre-infusion valve, - a dispensing time (Te) from the moment when the pre-infusion valve is opened to the moment when the pre-infusion valve is closed, - an opening time from the moment when the pre-infusion valve starts opening to the moment when the pre-infusion valve is completely open, - a maximum flow time in which the pre-infusion valve is completely open, and - a closing time from the moment when the pre-infusion valve starts closing to the moment when the pre-infusion valve is completely closed;