To provide a swash plate type variable displacement pump or a variable speed motor capable of providing a ball supporting the swash plate with prescribed hardness, favorably holding a lubricating operation, improving the durability of a counter-member constituting a bearing face of the ball, and reducing the vibration and noises by a low cost and simple constitution.

A base material for a support member 12 is composed of a general carbon steel, and its surface is covered with a thin film comprising carbide or carbonitride having high hardness HV 2,000-4,000 and a low friction coefficient. In this case, the hardness of the counter-ball bearing face of the swash plate 10 is preferably set to HV 700 or more. If the excessive concentrated load is applied to the ball 12 and causes micro rotation and sliding followed by the tilt rotation of the swash plate 10, the lubricating operation with the ball bearing can be held.