To prevent motor characteristics from deteriorating by the oxidation degradation of a metal and to improve the lifetime of a motor simultaneously in a metal graphite brush to be used in a field where much higher high-temperature high-humidity environmental characteristics are required.

In the metal graphite brush of this invention formed by adding a metal and a lubricant to graphite, bismuth or bismuth oxide is added in the range of 1.0 to 3.0 wt.%. The metal is copper and the lubricant is molybdenum disulfide.