A 3-phase 2-layer armature winding of a rotating electrical machine, comprising: three phase belts (17, 18), each phase belt (17, 18) of the winding having n parallel circuits, n being a natural number; upper coil pieces (15a, 15b) and lower coil pieces (16a, 16b) housed in two layers in a plurality of slots provided in a armature core, the upper coil pieces (15a, 15b) and lower coil pieces (16a, 16b) being sequentially connected in series at a connection side coil end and a counter-connection side coil end, forming one and the same phase, each phase belt (17, 18) having an output terminal lead-out connection conductor and a neutral terminal lead-out connection conductor at the connection side coil end; and the output terminal lead-out connection conductor being connected to an output terminal and being connected to a first specified coil piece (number 2 in Fig. 1) and the neutral terminal lead-out connection conductor being connected to a neutral terminal and being connected to a second specified coil piece (number 28 in Fig. 1), characterised in that the first specified coil piece (number 2 in Fig. 1) is positioned farther inside the phase belt than a first coil piece (number 1 in Fig. 1) counted from the end of said each phase belt, and a third specified coil piece (number 1 in Fig. 1) positioned at the end of the phase belt is connected by a jumper wire (20a, 20b) to a fourth specified coil piece (number 38 in Fig. 1) inside the phase belt from the other end of the phase belt (17, 18); wherein the upper coil pieces (15a or 15b) and lower coil pieces (16a or 16b) are sequentially connected between the first specified coil piece (number 2 in Fig. 1) and the second specified coil piece (number 28 in Fig. 1) in series using a jumper wire for the connection between the third specified coil piece (number 1 in Fig. 1) and the fourth specified coil piece (number 38 in Fig. 1). three phase belts (17, 18), each phase belt (17, 18) of the winding having n parallel circuits, n being a natural number; upper coil pieces (15a, 15b) and lower coil pieces (16a, 16b) housed in two layers in a plurality of slots provided in a armature core, the upper coil pieces (15a, 15b) and lower coil pieces (16a, 16b) being sequentially connected in series at a connection side coil end and a counter-connection side coil end, forming one and the same phase, each phase belt (17, 18) having an output terminal lead-out connection conductor and a neutral terminal lead-out connection conductor at the connection side coil end; and the output terminal lead-out connection conductor being connected to an output terminal and being connected to a first specified coil piece (number 2 in Fig. 1) and the neutral terminal lead-out connection conductor being connected to a neutral terminal and being connected to a second specified coil piece (number 28 in Fig. 1), characterised in that the first specified coil piece (number 2 in Fig. 1) is positioned farther inside the phase belt than a first coil piece (number 1 in Fig. 1) counted from the end of said each phase belt, and a third specified coil piece (number 1 in Fig. 1) positioned at the end of the phase belt is connected by a jumper wire (20a, 20b) to a fourth specified coil piece (number 38 in Fig. 1) inside the phase belt from the other end of the phase belt (17, 18); wherein the upper coil pieces (15a or 15b) and lower coil pieces (16a or 16b) are sequentially connected between the first specified coil piece (number 2 in Fig. 1) and the second specified coil piece (number 28 in Fig. 1) in series using a jumper wire for the connection between the third specified coil piece (number 1 in Fig. 1) and the fourth specified coil piece (number 38 in Fig. 1).