Patent ID: 8593045

Claim:
A spark plug comprising: a center electrode extending in an axial direction; a ceramic insulator surrounding a radial circumference of the center electrode; a metallic shell surrounding a radial circumference of the ceramic insulator and holding the ceramic insulator; and a ground electrode which is bent such that one end portion thereof and a forward end portion of the center electrode form a gap therebetween and whose other end portion is joined to the metallic shell; a small spark member which contains a noble metal as a main component being provided on at least one of the center electrode and the ground electrode at a position which faces the gap; the spark plug being characterized in that: the spark member has a weight of 1.5 mg or more, and the center electrode or the ground electrode on which the spark member is provided contains Ni as a main component, C in an amount of 0.005% by mass to 0.1% by mass, Si in an amount of 1.05% by mass to 3% by mass, Mn in an amount of 2% by mass or less, Cr in an amount of 20% by mass to 32% by mass, and Fe in an amount of 6% by mass to 16% by mass.