The frictional properties of a novel lubricant on a thin film magnetic medium are presented. The novel carboxylic amine salt has better frictional characteristics than the corresponding amide. The microscopic coverage of the lubricant film on the magnetic medium also is investigated by means of FTIR. Coverage does not change during reciprocating motion for the amine salt, which tightly anchors to the surface, since the friction coefficient is low and steady. The friction coefficient of the amine salt decreases with increasing lubricant on the surfaces. In contrast for the amide, the rubbing contact process breaks the lubricant film and results in high friction coefficient, since the amide has weak interaction with the surfaces. The friction coefficient is almost independent of the amount of the lubricant for the amide.