PROBLEM TO BE SOLVED: To provide a method which can be executed in controlling the filling of a balloon in such a manner that the vessel wall is not overstressed while the safe occlusion of the blood vessel is achieved in controlling the expansion of a balloon catheter arranged in a blood vessel.SOLUTION: This method includes a control and inflation device to control the filling of the balloon in such a manner that the vessel wall is not irreversibly deformed while the safe occlusion of the blood vessel is achieved.