A carbon brush is provided that inhibits the temperature increase and the increase of rubbing noise that result from excessive formation of a commutator film.
A carbon brush includes a carbon block substrate having pores in a surface thereof and an inner portion thereof, the carbon brush making sliding contact with a commutator provided in a motor. A suspension containing an oil and a petroleum-based solvent having a boiling point higher than a temperature of the carbon brush at a time of operation of the motor exists in the pores. It is desirable that the proportion of the suspension be from 0.5 weight % to 6 weight % with respect to the carbon block substrate.