An insulated bearing includes an outer ring, an inner ring, and a plurality of rolling elements. At least one of the outer ring and an inner ring is made of metal, the plurality of rolling elements are provided between the outer ring and the inner ring, so as to be freely rolled, and at least one of the outer ring and an inner ring is coated with an insulating layer. The insulating layer is formed of a mixture in which silicon carbide and/or aluminum nitride as an additive are/is dispersed in aluminum oxide as a base matrix. The content of the additive is 1 to 40 mass % with respect to the total amount of the mixture.