A split cage includes a plurality of cage segments each having a pair of rim portions and a pair of cage bar portions, the cage bar portions and the rim portions defining a single pocket that accommodates a single tapered roller. Turning of each of the cage segments is guided by the tapered roller, the cage segments being arranged in a circular pattern along the circumferential direction of the split cage, in an annular space between inner and outer rings. Each cage segment has projections formed so as to project radially inward and formed at the rim portions. A projecting length of each projection is set to such a length that the projection is brought into contact with an outer peripheral side portion of the inner ring when the cage segment starts rotating.