To provide a multipoint contact ball bearing whose joined inner rings are not separated with a retainer, without increasing the number of components.

The multipoint contact ball bearing includes inner and outer rings 2 and 4 which are relatively rotatably disposed facing each other, two or more balls 6 which roll between track grooves 2a and 4a which are formed in the inner and outer rings, and a retainer 8 which rotates between the track grooves while each ball is inserted in two or more pockets 82 which are arranged in its circumferential direction, wherein the outer ring contacts with each ball at one or two points in its track groove, the inner ring is constructed by assembling two annular bodies 22 and 24 which can be separated, and the annular bodies are formed with track grooves 22a and 24a which respectively contact with each ball at one point. The retainer is provided with a drop-off preventing portions 86 for preventing the ball inserted in the pocket from dropping-off depending on its own weight to the inner diameter side, and a plurality of clicks 88 in inner peripheries on both sides which project in a diameter reduction direction. The inner ring is provided with a depressions 2b (groove 22b and step 24b) formed by reducing the diameter of outer peripheries on both sides. The clicks are engaged with the depressions to assemble the two annular bodies.