Provided is a bearing structure, which can be simply worked and lowered in its manufacturing cost. The bearing structure (1) comprises a housing including a first housing portion (13) having a recess of a substantially semicircular section and a second housing portion (14) having a recess of a substantially semicircular section and forming a supporting hole (16) of a substantially circular section together with the recess (13a) of the first housing portion (13). Further comprised are two halved roller bearings (2) having a shaft (12) fitted therein. The two halved roller bearings (2) include one set of two halved outer rings (3a and 3b) arranged closely in the supporting hole (16) of that housing, a plurality of rolling elements (4) arranged to roll on the individual inner sides faces of the two halved outer rings (3a and 3b), and one set of two halved retainers (5a and 5b) for retaining the individual rolling elements (4) arranged substantially equidistantly in the circumferential direction. The internal diameter of the supporting hole (16) in the direction of the mating faces of the housing portions is made larger than the internal diameter in the direction displaced by 90 degrees from that of the mating faces.
