Abstract: A fastening system for a mucous membrane-supported denture is composed of a removable, mucous membrane-supported denture (3) and holding devices which effect a secure support during the wearing of the denture. The holding devices are composed of two greater than hemispherical heads (1) arranged either on natural teeth or on implants. The ball heads (1) are engaged in retaining caps (8) fastened in recesses (7) of the denture (3), the caps being composed of smooth, elastic plastic which contact the ball heads (1) only in the area of their equators M. Adapting rings (12) composed of a plastic material which is more elastic than that of the retaining caps (8) are arranged in the area of the openings (9) of the retaining caps (8) and effect a uniform contact of the retaining caps (8) on the ball heads (1). As a result, a secure support of the denture is achieved without a rigid connection between the ball heads (1) and the denture (3).