Abstract: A spark plug is specified, having a metal shell with an axial bore and a threaded section, having an insulator with an axial bore that is located at least partially inside the axial bore of the metal shell; a center electrode that is accommodated at least partially inside the axial bore of the insulator; a ground electrode that is held by the metal shell, wherein an end region of the ground electrode forms, together with the center electrode, an ignition gap, and having a sealing ring that extends at least between an outside shoulder of the insulator and an inside shoulder of the metal shell, wherein the sealing ring has polyaryl ether ketone (PAEK), preferably polyether ether ketone (PEEK).