Described is a glow plug with a glow pencil that comprises a forward end with a glow tip and a rearward end, a housing in which the rearward end of the glow pencil is arranged and in relation to which the glow pencil is movable in its longitudinal direction, and a bellows that is connected to the housing and the glow pencil. According to this disclosure, it is provided that a forward end of the bellows is attached to the housing and a rearward end of the bellows is attached to the glow pencil.