An IC tag 23 is fixed to a central portion of an axially outer end portion face of a hub 10a which is a rotational ring which makes up the wheel supporting bearing unit 5a. Historical information of the wheel supporting bearing unit 5a is stored in the IC tag 23. The historical information stored in the IC tag 23 can be read easily by the use of an external device 28. Due to this, the traceability of the wheel supporting bearing unit 5a can be increased.