An amount of undulation by which the inner surface 11 of a large-diameter-side flange portion 8 formed in an inner ring 5 is undulated is defined as an axial deflection &dgr;. And, the composite roughness of a contact portion between the inner surface 11 and the head portion 10 of a tapered roller 6 is expressed as &sgr;. A tapered roller bearing 1 is structured in such a manner that &dgr;≦8 &mgr;m and &sgr;≦0.22 &mgr;mRMS, or, &dgr;≦12 &mgr;m and &sgr;≦0.18 &mgr;, or, &dgr;≦16 &mgr;m and &sgr;≦0.13 &mgr;mRMS can be satisfied.