A pivot bearing 13 includes: a shaft 21; and a plurality of ball bearings 20 which are arranged in an axial direction with respect to the shaft 21 and each of which has an inner ring 27 fixed to the shaft 21 and an outer ring 25 fixed to a fixing hole 18 of an arm 16 via a tolerance ring 12, the pivot bearing being configured to swing around the shaft. The number of balls of each ball bearing 20 and the number of concave portions of the tolerance ring 12, which are configured to press the outer ring 25, are relatively prime to each other. Accordingly, it is possible to inexpensively make the reliable pivot bearing that achieves high precision with a simple structure, and thus a reliable high density magnetic recording apparatus is provided.