Mixing, stirring or dispersing method using a corresponding apparatus (1) with a housing (2) and a container (3). The container (3) has a mixing chamber (4), into which mixing chamber (4) a rod-like element (6) projects. At the entrance into the mixing chamber (4), this rod-like element (6) is connected to a membrane (8), which membrane (8) is part of a wall (9) of the container (3). In order to process the contents of the mixing chamber (4), the rod-like element (6) is made to move, together with the membrane (8), by a drive (7). In order to avoid unintentional failure of the membrane (8), within the context of the method, the number of revolutions of the drive (7) is counted and the drive is switched off upon reaching a maximum number of revolutions permitted for the loading capability of the membrane (8) and the resulting number of load variations.