A vehicle body comprising a canister holding structure for mounting, to the vehicle body, a canister having a cylindrical shape, the canister holding structure comprising: a holding member for holding the canister, the holding member including an annular portion which surrounds the circumference of a cylindrical portion of the canister and a fixing portion which is to be fixed to the vehicle body; and positioning means for positioning the canister at a predetermined position, the positioning means provided to the annular portion and the canister, characterized in that the canister has directivity in a direction orthogonal to an axial direction of the cylindrical shape, in such a manner that an axis of the cylindrical shape is directed in any direction other than a direction perpendicular to a ground surface, a large-diameter portion (41 a) is provided to the periphery of the cylindrical portion of the canister and in a central portion of the cylindrical portion of the canister in the axial direction, and a pair of holding members that cover substantially half a circumferential surface of the cylindrical portion with respect to the axial direction are attached to the cylindrical portion on both sides, in the axial direction, wherein the positioning means is configured of a plurality of recesses provided in both end portions of the large-diameter portion in the axial direction, and of a projection (42, 65) provided on the annular portion of the holding member and being adapted to engage with any one of the recesses, and a stopper portion is provided to the annular portion of the holding member, the stopper portion engaging with an end face portion of the large-diameter portion (41 a) in its axial direction thereby to restrict relative movement between the canister and the holding member in the axial direction, when the projection (42, 65) provided on the annular portion engages with one of the recesses, wherein a joint (44, 45) formed of a bent pipe to which piping (31, 32) is connected is provided at an end of the canister in the axial direction so as to be rotatable about the axis of the canister; the joint (44, 45) is provided with a flange portion that is connected to a through hole provided in the canister, and the canister is provided with: a retainer that engages with the flange portion so that the flange portion comes into intimate contact with the through hole; and a retainer holder that fixedly holds the retainer. a holding member for holding the canister, the holding member including an annular portion which surrounds the circumference of a cylindrical portion of the canister and a fixing portion which is to be fixed to the vehicle body; and positioning means for positioning the canister at a predetermined position, the positioning means provided to the annular portion and the canister, characterized in that the canister has directivity in a direction orthogonal to an axial direction of the cylindrical shape, in such a manner that an axis of the cylindrical shape is directed in any direction other than a direction perpendicular to a ground surface, a large-diameter portion (41 a) is provided to the periphery of the cylindrical portion of the canister and in a central portion of the cylindrical portion of the canister in the axial direction, and a pair of holding members that cover substantially half a circumferential surface of the cylindrical portion with respect to the axial direction are attached to the cylindrical portion on both sides, in the axial direction, wherein the positioning means is configured of a plurality of recesses provided in both end portions of the large-diameter portion in the axial direction, and of a projection (42, 65) provided on the annular portion of the holding member and being adapted to engage with any one of the recesses, and a stopper portion is provided to the annular portion of the holding member, the stopper portion engaging with an end face portion of the large-diameter portion (41 a) in its axial direction thereby to restrict relative movement between the canister and the holding member in the axial direction, when the projection (42, 65) provided on the annular portion engages with one of the recesses, wherein a joint (44, 45) formed of a bent pipe to which piping (31, 32) is connected is provided at an end of the canister in the axial direction so as to be rotatable about the axis of the canister; the joint (44, 45) is provided with a flange portion that is connected to a through hole provided in the canister, and the canister is provided with: a retainer that engages with the flange portion so that the flange portion comes into intimate contact with the through hole; and a retainer holder that fixedly holds the retainer.