The invention relates to a non-rotationally symmetrical spark gap, in particular a horn spark gap with a deion chamber, a multi-part insulating material housing (1) as a support and receiving body for the horn electrodes and the deion chamber, means for conducting the gas flow related to the arc, wherein the insulating material housing (1) is divided on the plane defined by the horn electrodes and has two half shells, and plug or screw connections (4, 5) which lead out on the end face. According to the invention, with the exception of the sections of the plug or screw connections (4, 5) leading out, the insulating material housing is surrounded on all sides by a cooling surface (14) which is near the housing and lies against the housing surface, and the cooling surface (14) is at least partly supported on webs (8) which are designed to conduct the gas flow on the outer surface of the half shells.