PURPOSE: To make the crystal grains of the resulting titled material fine, to prevent the wear at high temp. and the formation of an oxide film on the surface, to improve the weldability and to facilitate ignition by dispersing a small amount of ZrO2 or ThO2 as metallic oxide in Pt.

CONSTITUTION: This material for an ignition plug is obtd. by dispersing 0.01W 2wt% ZrO2 or ThO2 in 98W99.99wt% Pt. When a plug body made of this material is used at a high temp. over a long term, the crystal grains do not grow, and because of the low metallic oxide content, the chemical and physical properties are similar to those of pure Pt and stable. This material has high weldability to the Ni base, and since no base metal is contained, when the material is heated to a high temp., the formation of an oxide film on the surface is prevented, facilitating ignition.