A rotary electric rotor comprising: a rotor shaft having a male screw portion on a first side in an axial direction of the rotor shaft and having a core receiving portion on a second side in the axial direction of the rotor shaft; a rotor core having a shaft through-hole for the rotor shaft, in which the rotor shaft is inserted into the shaft through-hole of the rotor core, and one end portion of the rotor core is in contact with the core receiving portion of the rotor shaft; a washer having an annular structure, in which the washer has cutouts (44, 46), the washer being disposed so as to be in contact with a second end surface of the rotor core, a surface on an opposite side of a surface of the washer in contact with the second end surface of the rotor core being a tapered surface of which a side disposed radially outward from the rotor shaft is configured to be farther from the second end surface of the rotor core than a side disposed radially inward to the rotor shaft; and a nut having a female screw portion, meshing with and being fixed to the male screw portion of the rotor shaft, and having a first end surface in contact with the tapered surface of the washer, in which the first end surface of the nut is a tapered surface of which a side disposed radially inward to the rotor shaft protrudes closer to the washer side than a side disposed radially outward from the rotor shaft characterized in that the cutouts (44, 46) of the washer are configured to cause the washer to be elastically deformable in a radial direction, and in that the surface of the washer in contact with the second end surface of the rotor core has an annular projection portion extending in the axial direction of the rotor shaft, the annular projection portion is positioned in a gap between an inner circumferential surface of the shaft through-hole of the rotor core and an outer circumferential surface of the rotor shaft, wherein the tapered surface of the nut is pressed to the tapered surface of the washer such that the annular projection portion of the washer is widened in an outer circumferential direction, pressing the annular projection portion of the washer to the inner circumferential surface of the rotor core so that the annular projection portion is fitted and fixed to the inner circumferential surface of the shaft through-hole of the rotor core. a rotor shaft having a male screw portion on a first side in an axial direction of the rotor shaft and having a core receiving portion on a second side in the axial direction of the rotor shaft; a rotor core having a shaft through-hole for the rotor shaft, in which the rotor shaft is inserted into the shaft through-hole of the rotor core, and one end portion of the rotor core is in contact with the core receiving portion of the rotor shaft; a washer having an annular structure, in which the washer has cutouts (44, 46), the washer being disposed so as to be in contact with a second end surface of the rotor core, a surface on an opposite side of a surface of the washer in contact with the second end surface of the rotor core being a tapered surface of which a side disposed radially outward from the rotor shaft is configured to be farther from the second end surface of the rotor core than a side disposed radially inward to the rotor shaft; and a nut having a female screw portion, meshing with and being fixed to the male screw portion of the rotor shaft, and having a first end surface in contact with the tapered surface of the washer, in which the first end surface of the nut is a tapered surface of which a side disposed radially inward to the rotor shaft protrudes closer to the washer side than a side disposed radially outward from the rotor shaft characterized in that the cutouts (44, 46) of the washer are configured to cause the washer to be elastically deformable in a radial direction, and in that the surface of the washer in contact with the second end surface of the rotor core has an annular projection portion extending in the axial direction of the rotor shaft, the annular projection portion is positioned in a gap between an inner circumferential surface of the shaft through-hole of the rotor core and an outer circumferential surface of the rotor shaft, wherein the tapered surface of the nut is pressed to the tapered surface of the washer such that the annular projection portion of the washer is widened in an outer circumferential direction, pressing the annular projection portion of the washer to the inner circumferential surface of the rotor core so that the annular projection portion is fitted and fixed to the inner circumferential surface of the shaft through-hole of the rotor core.