A ball bearing in which an annular cage with a plurality of pockets formed through
the annular cage is incorporated between inner and outer rings, a ball is housed
in each pocket, the annular cage is guided by the outer ring, and a relationship
between a radial clearance (guide clearance) of the annular cage with respect
to the outer ring and an axial clearance (pocket clearance) of an inner
wall face of the pocket with respect to the ball is set at .