A method of manufacturing a stator includes the steps of: (1) forming substantially planar electric wires each of which includes in-slot portions to be received in slots of a stator core and turn portions to be located outside the slots to connect adjacent pairs of the in-slot portions; (2) rolling each of the planar electric wires by more than one turn into a spiral shape; (3) forming a stator coil by assembling the rolled electric wires through elastic deformation thereof; and (4) assembling the stator core and the stator coil to form the stator. Further, in the rolling step, each of the planar electric wires is rolled by plastically deforming the turn portions into circumferentially-extending sections each having a predetermined curvature. Furthermore, a curvature ratio of a radially-outermost one of the circumferentially-extending sections is set to be greater than that of a radially-innermost one of the same.