To provide a cover, increasing the fitting strength to a cover of a sensor part by restraining the generation of porosity, and lowering the cost.

This cover with a sensor for a wheel bearing device is fitted to an outer ring member 2 of a wheel bearing device, and made of metal. The cover is provided with the sensor part 7 for detecting the rotation of an inner ring member 12 rotatably disposed on the inside diameter side of the outer ring member 2 through a rolling element. A connector 5 of the sensor 7 part is formed of a substantially cylinderical body, one end of which is provided with a flange part 5a, and the flange part 5a is disposed in contact with the outer surface of the cover 1 to be substantially coaxial with a through hole 3 formed in the cover 1. A synthetic resin is molded to cover the sensor element 6 and enter the connector 5 through the through hole 3, and the synthetic resin part entering the connector 5 and the inner edge part 5b of the flange part 5a of the connector 5 are engaged with each other.