A circuit breaker with a first contact sleeve (3, 14), a second contact sleeve (4, 16), an insulating sleeve (5, 18) disposed between the first contact sleeve (3, 14) and the second contact sleeve (4, 16) has a switching piston (6, 20) with at least one contact section (8) and an isolating section (7, 19), which is disposed at the side of the contact section (8), whereby the switching piston (6, 20) is movable between a closed position in which the contact section (8) of switching piston (6, 20) connects the first contact sleeve (3, 14) with the second contact sleeve (4, 16) so as to be electrically conductive, and an open position in which the contact section (8) of the switching piston (6, 20) does not connect the first contact sleeve (3, 14) with the second contact sleeve (4, 16), in which the first contact sleeve (3, 14), second contact sleeve (4, 16) and insulating sleeve (5, 18) is movable. The isolating section (7, 19) is elastically deformable and in the insulating sleeve (5, 18) exerts a surface pressure force on the surface thereof due to elastic deformation. The circuit breaker according to the invention is reclosable.