| 摘要 |
Provided is a spark plug such that overheating of a ground electrode is more reliably prevented while resistance to oxidation is sufficiently improved. This spark plug (1) is equipped with a main metal fitting (3) and a ground electrode (27). The ground electrode (27) has an electrode base section (271) which extends from the leading end of the main metal fitting (3) toward the leading end side of the spark plug, a bent section (272) one end of which continues from the leading end of the electrode base section (271), and an electrode leading end section (273) which extends from the other end of the bent section (272) and forms a spark-discharge gap (28) with a center electrode (5). Of the sections of the ground electrode (27), at least the electrode leading end section (273) thereof has a coating layer (31) comprising a material having superior oxidation resistance to the oxidation resistance of the base material of the ground electrode (27), said coating layer (31) being disposed at least on the leading end surface (27F) and outer surfaces excluding the surface (27A) positioned on the side toward the center electrode (5). The base material of the ground electrode (27) is exposed at least at a portion of the electrode base section (271). |
