A method of manufacturing a rolling bearing unit for supporting a wheel, the rolling bearing unit comprising: a hub main body having an outer-side inner ring track that is formed on an outer circumferential surface of an intermediate section of the hub main body in an axial direction; and an inner ring that has an inner-side inner ring track formed on an outer circumferential surface of the inner ring and that is fitted onto a portion of the hub main body close to an inner end of the hub main body in the axial direction, wherein the inner ring is fixed to the hub main body by pressing an inner end surface of the inner ring in the axial direction with a caulking section, the caulking section being formed by plastically deforming a cylindrical section, installed on an inner end portion of the hub main body in the axial direction, outward in a radial direction, and the caulking section is formed by pressing a roll against the cylindrical section while the roll is rotated about a central axis of the hub main body by an electric motor, the roll being supported in a rotatable state about a central axis of the roll which is inclined with respect to a central axis (α 7) of the hub main body, the method of manufacturing a rolling bearing unit for supporting a wheel comprising: detecting a rotational torque generated by the electric motor or a physical amount having a correlation with the rotational torque during a caulking process for forming the caulking section, characterized in that the method further comprises: determining a condition for terminating the caulking process on the basis of the detection result. the rolling bearing unit comprising: a hub main body having an outer-side inner ring track that is formed on an outer circumferential surface of an intermediate section of the hub main body in an axial direction; and an inner ring that has an inner-side inner ring track formed on an outer circumferential surface of the inner ring and that is fitted onto a portion of the hub main body close to an inner end of the hub main body in the axial direction, wherein the inner ring is fixed to the hub main body by pressing an inner end surface of the inner ring in the axial direction with a caulking section, the caulking section being formed by plastically deforming a cylindrical section, installed on an inner end portion of the hub main body in the axial direction, outward in a radial direction, and the caulking section is formed by pressing a roll against the cylindrical section while the roll is rotated about a central axis of the hub main body by an electric motor, the roll being supported in a rotatable state about a central axis of the roll which is inclined with respect to a central axis (α 7) of the hub main body, a hub main body having an outer-side inner ring track that is formed on an outer circumferential surface of an intermediate section of the hub main body in an axial direction; and an inner ring that has an inner-side inner ring track formed on an outer circumferential surface of the inner ring and that is fitted onto a portion of the hub main body close to an inner end of the hub main body in the axial direction, wherein the inner ring is fixed to the hub main body by pressing an inner end surface of the inner ring in the axial direction with a caulking section, the caulking section being formed by plastically deforming a cylindrical section, installed on an inner end portion of the hub main body in the axial direction, outward in a radial direction, and the caulking section is formed by pressing a roll against the cylindrical section while the roll is rotated about a central axis of the hub main body by an electric motor, the roll being supported in a rotatable state about a central axis of the roll which is inclined with respect to a central axis (α 7) of the hub main body, the method of manufacturing a rolling bearing unit for supporting a wheel comprising: detecting a rotational torque generated by the electric motor or a physical amount having a correlation with the rotational torque during a caulking process for forming the caulking section, characterized in that the method further comprises: determining a condition for terminating the caulking process on the basis of the detection result.