PURPOSE: To improve the durability by making a ball holder of lead-included copper group metal, and forming lead film on the ball rolling surface of an inner ring or an outer ring opposite to a rotating member, and forming film of molybdenum disulfide on the surface which contacts to other members.

CONSTITUTION: In a holder 9, an annular member 13 is made of copper group metal including lead such as lead bronze, and a pocket hole 14 for a ball 10 is formed by machining. Lead film 16 is formed on the ball rolling subrace 15 of an inner ring 7 opposite to a rotary shaft 2, and film 17 of molybdenum disulfide is formed on the surface of the inner ring 7 except for the ball rolling surface 15 by spattering. With this structure, the lead film 16 works as lubricant of the ball 10 at the initial stage of the rotation, and the lead converged to the ball 10 works to extract the lead included in the holder 9.