A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.