A tube constriction valve has a valve body (1) with an approximation sensor (3) and a clamping bolt (2) that squeezes the tube inside the valve body (1). The approximation sensor (3) detects the position of the tube constriction valve and can indicate corresponding data by an approximation element (4) on the clamping bolt (2). The tube constriction valve allows for automatic and also manual operation and at the same time contains a position indicator. Consequently, damage to the tube is prevented and processing reliability preserved.