A rotating electrical machine (200; 202), comprising: a stator core having a plurality of slots formed therein; a stator winding assuming a plurality of phases (U, V, W), which includes a plurality of round windings (U11-U24, V11-V24, W11-W24) wound with a wave winding pattern, each having slot conductors each inserted at one of the slots at the stator core to form one of a plurality of layers (L1-L4) and cross conductors each connecting same-side ends of slot conductors inserted at different slots so as to form a coil end; and a rotor rotatably supported with an air gap so as to be allowed to rotate relative to the stator core, wherein: the cross conductors connect the slot conductors so as to run astride slots with the slot pitch Np set to N + 1 at coil ends on one side and run astride slots with the slot pitch Np set to N - 1 at coil ends on another side, with N representing a number of slots per pole; the stator winding includes a plurality of stator winding groups (U1, U2), wherein each of the stator winding groups (U1, U2) includes a plurality of the round windings of the same phase and wherein the stator winding groups (U1, U2) are connected in parallel and the round windings of the respective stator winding groups (U1, U2) are arranged such that no phase difference manifests between voltages induced at each of the stator winding groups of the same phase; the stator winding includes a plurality of slot conductor groups each having a plurality of slot conductors corresponding to a single phase (U, V or W); the plurality of slot conductors in each slot conductor group are inserted at a predetermined number Ns of successive slots forming a continuous range along a circumference of the stator core so that the slot conductors in the slot conductor group take successive slot positions and successive layer positions; and the predetermined number Ns is set so that Ns = NSPP + NL when NSPP represents a number of slots per phase per pole and a number of layers (L1-L4) is expressed as 2 x NL. a stator core having a plurality of slots formed therein; a stator winding assuming a plurality of phases (U, V, W), which includes a plurality of round windings (U11-U24, V11-V24, W11-W24) wound with a wave winding pattern, each having slot conductors each inserted at one of the slots at the stator core to form one of a plurality of layers (L1-L4) and cross conductors each connecting same-side ends of slot conductors inserted at different slots so as to form a coil end; and a rotor rotatably supported with an air gap so as to be allowed to rotate relative to the stator core, wherein: the cross conductors connect the slot conductors so as to run astride slots with the slot pitch Np set to N + 1 at coil ends on one side and run astride slots with the slot pitch Np set to N - 1 at coil ends on another side, with N representing a number of slots per pole; the stator winding includes a plurality of stator winding groups (U1, U2), wherein each of the stator winding groups (U1, U2) includes a plurality of the round windings of the same phase and wherein the stator winding groups (U1, U2) are connected in parallel and the round windings of the respective stator winding groups (U1, U2) are arranged such that no phase difference manifests between voltages induced at each of the stator winding groups of the same phase; the stator winding includes a plurality of slot conductor groups each having a plurality of slot conductors corresponding to a single phase (U, V or W); the plurality of slot conductors in each slot conductor group are inserted at a predetermined number Ns of successive slots forming a continuous range along a circumference of the stator core so that the slot conductors in the slot conductor group take successive slot positions and successive layer positions; and the predetermined number Ns is set so that Ns = NSPP + NL when NSPP represents a number of slots per phase per pole and a number of layers (L1-L4) is expressed as 2 x NL. the cross conductors connect the slot conductors so as to run astride slots with the slot pitch Np set to N + 1 at coil ends on one side and run astride slots with the slot pitch Np set to N - 1 at coil ends on another side, with N representing a number of slots per pole; the stator winding includes a plurality of stator winding groups (U1, U2), wherein each of the stator winding groups (U1, U2) includes a plurality of the round windings of the same phase and wherein the stator winding groups (U1, U2) are connected in parallel and the round windings of the respective stator winding groups (U1, U2) are arranged such that no phase difference manifests between voltages induced at each of the stator winding groups of the same phase; the stator winding includes a plurality of slot conductor groups each having a plurality of slot conductors corresponding to a single phase (U, V or W); the plurality of slot conductors in each slot conductor group are inserted at a predetermined number Ns of successive slots forming a continuous range along a circumference of the stator core so that the slot conductors in the slot conductor group take successive slot positions and successive layer positions; and the predetermined number Ns is set so that Ns = NSPP + NL when NSPP represents a number of slots per phase per pole and a number of layers (L1-L4) is expressed as 2 x NL.