A split cage comprising a plurality of cage segments, each of the cage segments having a pair of rim portions (21, 22) that face each other at a prescribed distance in an axial direction of the split cage, and a plurality of cage bar portions (23, 24) disposed between the rim portions (21, 22) to connect the rim portions (21, 22) to each other, the cage bar portions (23, 24) and the rim portions (21, 22) defining a pocket that accommodates a roller, and a pocket-side side face (23a, 24a) of each of the cage bar portions (23, 24) being a pocket-side face (23a, 24a) that is allowed to be in sliding contact with an outer peripheral face of the roller, wherein: turning of each of the cage segments is in use guided by the roller, the cage segments being arranged in a circular pattern along a circumferential direction of the split cage, in an annular space between an inner ring and an outer ring; characterized in that a radial clearance (S4, S5), in a state where the rotation axis of the roller and a rotational axis of the cage segment coincide with each other, between a radially inner portion of the pocket-side face (23a, 24a) of each of the cage bar portions (23, 24) and the outer peripheral face of the roller is set larger than an amount of change (Δd) in a pitch circle radius of the cage segment when the cage segment is displaced radially outward due to thermal expansion, the pocket-side face (23a, 24a) has a radially inner tilted face (23a1, 24a1) that is formed so as to be tilted such that part of the inner tilted face (23a1, 24a1), except a radially inner end of the pocket-side face (23a, 24a), is in contact with the outer peripheral face of the roller, and a radially outer tilted face (23a2, 24a2) that is formed at a position radially outward of the inner tilted face (23a1, 24a1) so as to be tilted such that part of the outer tilted face (23a2, 24a2) except a radially outer end of the pocket-side face (23a, 24a) is in contact with the outer peripheral face of the roller, wherein the radially outer tilted face (23a2, 24a2) is formed in the center portion of the cage bar portion (23, 24) and does not contact both of the rim portions (21,22). turning of each of the cage segments is in use guided by the roller, the cage segments being arranged in a circular pattern along a circumferential direction of the split cage, in an annular space between an inner ring and an outer ring; characterized in that a radial clearance (S4, S5), in a state where the rotation axis of the roller and a rotational axis of the cage segment coincide with each other, between a radially inner portion of the pocket-side face (23a, 24a) of each of the cage bar portions (23, 24) and the outer peripheral face of the roller is set larger than an amount of change (Δd) in a pitch circle radius of the cage segment when the cage segment is displaced radially outward due to thermal expansion, the pocket-side face (23a, 24a) has a radially inner tilted face (23a1, 24a1) that is formed so as to be tilted such that part of the inner tilted face (23a1, 24a1), except a radially inner end of the pocket-side face (23a, 24a), is in contact with the outer peripheral face of the roller, and a radially outer tilted face (23a2, 24a2) that is formed at a position radially outward of the inner tilted face (23a1, 24a1) so as to be tilted such that part of the outer tilted face (23a2, 24a2) except a radially outer end of the pocket-side face (23a, 24a) is in contact with the outer peripheral face of the roller, wherein the radially outer tilted face (23a2, 24a2) is formed in the center portion of the cage bar portion (23, 24) and does not contact both of the rim portions (21,22).