The invention relates to a method for the surface blasting of hollow spaces or cavities, especially of cavities of gas turbines. According to the invention, shot balls are accelerated with the aid of at least one vibrator, whereby the shot balls accelerated in the ultrasonic range are directed onto surfaces of a cavity that is to be blasted. In that regard, the vibrator is preferably positioned with a small spacing distance, preferably with a spacing distance on the order of magnitude of the diameter of the shot balls utilized for the blasting, from the cavity to be blasted.