To provide a bearing device eliminating the need of the structural improvement of a pulsar ring required to set a gap between a sensor detection surface and the detected surface of the pulsar ring, and simplifying an assembly operation.

This bearing device comprises an inward member 1 and an outward member 2, and double row rolling elements 3 stored between these members 1 and 2. The pulsar ring 5 is inserted onto the inward member 2 between the double row rolling elements 3 and 3. A sensor 6 is installed aslant on the outward member 2 opposedly to the pulsar ring 5. The outer diameter surface of the pulsar ring 5 is formed with a surface parallel with the axial center O of the inward member 1, and the gap between the detected surface of the sensor 6 opposed to the pulsar ring 5 and the detected surface of the pulsar ring 5 is uniform in the axial direction.