To provide a rolling bearing which secures high radial rigidity while maintaining reliability and high-speed property without increasing surface pres sure and torque by adjusting a radius of curvature of raceway surfaces for inner and outer rings.

The rolling bearing comprises an outer ring 2 having an outer ring raceway 2a on its inner peripheral surface; an inner ring 3 having an inner ring raceway 3a on its outer peripheral surface; and balls 4 retained freely rollable between the outer ring raceway surface 2a and the inner ring raceway surface 3a, and is rotatably supported to a fixed shaft 6, wherein the expression: 1%≤(re-ri)/Da≤4% is satisfied when a radius of curvature of the outer ring raceway surface 2a is assumed as re, a radius of curvature of the inner ring raceway surface 3a as ri, and a ball diameter as Da.