1. The heart valve prosthesis comprising an annular support structure (3) attachable to the ring valve, and a valve flap (5) of flexible material supported by the supporting structure in a floating state, wherein the supporting structure chtou are part of a carrier wall (31 ), which is connected with a fixed end (51) of the valve flap and the part in the form of an additional wall (32) opposite the supporting wall, and provided with a static or quasi-static surface (33) koaptatsii which is adapted POSSIBILITY sealingly mate with the free end (52) of the valve flap (5) and has an extension in a direction substantially parallel to the direction of movement of the free end (52) of the valve flap (5) near the surface (33) koaptatsii, the free end of the valve flap (5) connected to the supporting wall (31) or with an additional wall (32) by means of at least one strand (55) of flexible material, the length of which is selected to provide the termination of movement of the free end (52) of the valve flap (5) at the surface (33 ) koaptatsii.2. Prosthesis according to Claim. 1, wherein the surface (33) koaptatsii has a length (h) in a direction parallel to the direction of movement of the free end (52) of the valve flap (5) of at least 5 mm.3. Prosthesis according to Claim. 1, wherein the surface (33) formed inner side koaptatsii additional wall (32) supporting structure (3) .4. Prosthesis according to Claim. 1, wherein the surface (33) koaptatsii formed quasistatic flap (6) koaptatsii having a fixed end (61) connected to an additional wall (32) and a free end (62) connected to a supporting wall (31) or with an additional wall (32) by means of at1. Протез сердечного клапана, содержащий кольцевую поддерживающую конструкцию (3), прикрепляемую к кольцу клапана, и клапанную створку (5) из гибкого материала, поддерживаемую поддерживающей конструкцией в плавающем состоянии, отличающийся тем, чтоу поддерживающей конструкции имеются часть в виде несущей стенки (31), с которой соеди
