Abstract: The invention relates to an apparatus for surface processing or surface treatment by means of dry ice granulate, with a reservoir for receiving a dry ice medium, in particular dry ice pellets, an inlet for the feed of a propellant medium, an outlet for the supply of a mixture of propellant medium and dry ice granulate to a blast gun, and an outflow chamber lying therebetween, there being arranged in the path between the reservoir and the outflow chamber a grinding mechanism, which is formed so as to comminute the dry ice medium to dry ice granulate with a particle size in a prescribed range, and a transport roll (4) being arranged between the grinding mechanism (3) and the outflow chamber (59), the transport roll (4) being operable with a variable speed so as to vary the quantity of the particles of the dry ice granulate per unit time. Furthermore, the invention relates to a corresponding method and the use of the method.