A milking system includes a vacuum pump (11); milking equipment (15); a conduit (14) connecting the milking equipment to the vacuum pump; and a first vacuum regulator (25) provided to maintain a preset vacuum level in the milking equipment. A second vacuum regulator (27, 29, 30a) is arranged between the first vacuum regulator and the vacuum pump and is provided for regulating the preset vacuum to a desired level. Preferably, the second vacuum regulator includes a pressure sensor (30a) provided for measuring a pressure level in the milking system; adjustable air admitting elements (31), e.g. a solenoid valve, provided for admitting air to enter the conduit; and a control device (29) provided for controlling the second vacuum regulator depending on the measured pressure level.