The invention relates to a valve system consisting of a vacuum valve and a regulating unit. The vacuum valve has a valve seat which has a valve opening and a first seal surface which runs around the valve opening, and the vacuum valve has a valve closure for closing the valve opening in a substantially gas-tight manner with a second seal surface corresponding to the first seal surface. A drive unit coupled to the valve closure is designed such that the valve closure can be varied and adjusted in a defined manner in order to provide respective valve opening states which depend on respective states of the valve closure. The regulating unit is designed to carry out a controlled variation or adjustment of the regulating process which provides the valve opening state by actuating the drive unit on the basis of a currently determined regulating variable for a process parameter and a target variable. The regulating unit has a checking function for monitoring the regulating process, said function being configured such that a series of states of the valve closure are detected over at least a period of time of the regulating process upon carrying out the checking function as part of the regulating process, and the states are stored as current regulating data (21a); the current regulating data (21a) is compared with specified target regulating data (20, 20a); and process information is generated on the basis of the comparison of the current regulating data (21a) with the target regulating data (20, 20a).