The article deals with the milking machine vacuum system which is designed for the vacuum level control with a special reducing valve. Vacuum Milking machines with the vacuum pumps without frequency converter have the constant rotation speed and vacuum level is controlled by the control valve. By using the frequency converter for controlling electric motor of vacuum pump the electric energy consumption significantly decreases but the vacuum fluctuation is higher. The vacuum pump of the designed vacuum system is connected to the air container. The vacuum level of the air container is controlled by the frequency converter on a higher level than the level of the milking vacuum. Newly designed reducing valve is placed between the air container and the vacuum pipeline system of the milking machine. The reducing valve controls the air which flows through it and the vacuum is reduced on the required level and is stabilized. But the energy consumption is a little bit higher.