Balls are interposed between respective raceway surfaces of inner and outer ring members, and a seal apparatus is provided between shoulder portions of the inner and outer ring members. The seal apparatus comprises an outer ring-side seal ring fixed to the outer ring member, and an inner ring-side seal ring fixed to the inner ring member. A pulser ring is fixed to a ring-shaped core metal of the inner ring-side seal ring. In an outer diameter side of the ring-shaped core metal of the outer ring-side seal ring, a magnetic sensor is molded with resin by an external member to be integrated therein. A connector connected to the magnetic sensor is formed consecutive with the external member.