Abstract: In a tapered roller bearing, the surface roughness of at least a rolling surface and a large diameter-side end surface of a tapered roller is 0.02 to 0.17 ?m in protruding mountain portion height Rpk, 0.12 to 0.21 ?m in core portion level difference Rk, and 0.07 to 0.43 ?m in protruding valley portion height Rvk and the average recessed portion area in the fine irregularities on the surface of the tapered roller is 5 ?m2 or less. As a result, oil film formability can be improved under dilute lubrication and a decline in lubricating oil viscosity and surface damage at a rolling contact part and an increase in friction at a sliding contact part can be suppressed at the same time.

Abstract: In a tapered roller bearing (10), the surface roughness of at least a rolling surface (13c) and a large diameter-side end surface (13b) of a tapered roller (13) is 0.02 to 0.17 ?m in reduced peak height Rpk, 0.12 to 0.21 ?m in core roughness depth Rk, and 0.07 to 0.43 ?m in reduced valley depth Rvk and the average recessed portion area in the fine irregularities on the surface of the tapered roller (13) is 5 ?m2 or less. As a result, oil film formability can be improved under dilute lubrication and a decline in lubricating oil viscosity and surface damage at a rolling contact part and an increase in friction at a sliding contact part can be suppressed at the same time.