SPARK PLUG

To provide a spark plug capable of improving maintainability without sacrificing thermal conductivity.SOLUTION: A spark plug includes: a cylindrical main metallic shell; a center electrode which is supported by the main metallic shell in an electrically insulated state and in which a tip of the center electrode is arranged at a position closer to a tip side of the spark plug than a tip end surface of a tip of the main metallic shell; and a ground electrode in which one end of the ground electrode is connected to a tip facing surface of the main metallic shell and forms a spark gap between the other end of the ground electrode and the tip of the center electrode. A cap is further provided which is arranged on the tip end side of the main metallic shell, the cap covers the center electrode and the other end of the ground electrode from the tip end side, a rear end facing surface of the cap faces the tip facing surface, a notch is provided on the rear end facing surface to arrange the one end of the ground electrode, and the main metallic shell and the cap are detachably configured.SELECTED DRAWING: Figure 1 【課題】熱伝導性を確保しつつメンテナンス性を向上できるスパークプラグを提供する。【解決手段】スパークプラグは、筒状の主体金具と、主体金具に絶縁保持され、自身の先端が主体金具の先端部の先端面より先端側に配置される中心電極と、主体金具の先端向き面に自身の一端部が接続され、自身の他端部と中心電極の先端との間に火花ギャップを形成する接地電極と、を備える。主体金具の先端側に配置されるキャップをさらに備え、キャップは、中心電極および接地電極の他端部を先端側から覆い、キャップの後端向き面は主体金具の先端向き面に対面し、後端向き面には、接地電極の一端部が配置される切込みが設けられ、主体金具とキャップは分離可能に構成されている。【選択図】図１