The present invention discloses a spacer retainer in a cross roller bearing. More specifically, in a cross roller bearing comprising an inner race having a V-shaped groove with an angle of approximately 90 degrees formed in the outer periphery thereof, a bisplit outer race having a V-shaped groove with an angle of approximately 90 degrees formed in the inner periphery thereof, and rollers disposed in those V-shaped grooves in an alternately crossing manner through spacer retainers, the spacer retainers are each provided atboth side ends thereof with curved surfaces perpendicularly intersecting each other, the curved surfaces being each formed as a curved concave surface having a radius of curvature somewhat larger than that of the roller, with a larger side thickness of a starting edge circle of the curved concave surface being smaller than a smaller side thickness of a terminating edge circle of the curved concave surface, and the spacer retainer is further provided with an axially extending oil reservoiring through hole formed therein.