A 3-phase even-numbered-pole 2-layered armature winding housed in 45 slots per pole provided in a laminated iron core of a rotating electrical machine, comprising: six parallel circuits provided for each phase of the winding and divided into a pair of phase belts including first and second phase belts (17, 18), each parallel circuit including upper and lower coil pieces (15, 16) which are connected to each other in series in a connection side coil end and a counter-connection side coil end, wherein, when relative positions of each of the upper and lower coil pieces (15, 16) in one phase belt are numbered sequentially from a pole center, each of the upper and lower coil pieces (15, 16) are classified into five coil piece groups placed in first to third positions, fourth to sixth positions, seventh to ninth position, tenth to twelfth position, and thirteenth to fifteenth positions from the pole center, three coil pieces (15, 16) of first, second, and third parallel circuits are arranged in each coil piece group of the first phase belt, and three coil pieces (15, 16) of fourth, fifth, and sixth parallel circuits are arranged in each coil piece group of the second phase belt, in each coil piece group of each phase belt, the coil pieces (15, 16) of the second and fifth parallel circuits are placed in the second positions from the pole center among three positions of coil pieces in corresponding coil piece group, in six or four groups out of ten coil piece groups of each phase belt, coil pieces (15, 16) of the first or fourth parallel circuit are placed in the first position from the pole center among three positions of coil pieces in corresponding coil piece group, and in first and second coil piece groups placed in the first and second positions from the pole center out of coil piece groups of each phase belt, coil pieces (15, 16) of the first or fourth parallel circuit are placed in different-numbered positions from the pole center among three positions of coil pieces in corresponding coil piece group to be differently between the first and second coil piece groups, characterized in that: the upper coil pieces of the first and fourth parallel circuits are placed in the 3rd, 4th, 7th, 10th, and 15th positions from the pole center, the lower coil pieces of the first and fourth parallel circuits are placed in the 1st, 6th, 9th, 10th, and 13th positions from the pole center, the upper and lower coil pieces (15, 16) of the second and fifth parallel circuits are placed in the 2nd, 5th, 8th, 11th, and 14th positions from the pole center, the upper coil pieces of the third and sixth parallel circuits are placed in the 1st, 6th, 9th, 12th, and 13th positions from the pole center, and the lower coil pieces of the third and sixth parallel circuits are placed in the 3rd, 4th, 7th, 12th, and 15th positions from the pole center. six parallel circuits provided for each phase of the winding and divided into a pair of phase belts including first and second phase belts (17, 18), each parallel circuit including upper and lower coil pieces (15, 16) which are connected to each other in series in a connection side coil end and a counter-connection side coil end, wherein, when relative positions of each of the upper and lower coil pieces (15, 16) in one phase belt are numbered sequentially from a pole center, each of the upper and lower coil pieces (15, 16) are classified into five coil piece groups placed in first to third positions, fourth to sixth positions, seventh to ninth position, tenth to twelfth position, and thirteenth to fifteenth positions from the pole center, three coil pieces (15, 16) of first, second, and third parallel circuits are arranged in each coil piece group of the first phase belt, and three coil pieces (15, 16) of fourth, fifth, and sixth parallel circuits are arranged in each coil piece group of the second phase belt, in each coil piece group of each phase belt, the coil pieces (15, 16) of the second and fifth parallel circuits are placed in the second positions from the pole center among three positions of coil pieces in corresponding coil piece group, in six or four groups out of ten coil piece groups of each phase belt, coil pieces (15, 16) of the first or fourth parallel circuit are placed in the first position from the pole center among three positions of coil pieces in corresponding coil piece group, and in first and second coil piece groups placed in the first and second positions from the pole center out of coil piece groups of each phase belt, coil pieces (15, 16) of the first or fourth parallel circuit are placed in different-numbered positions from the pole center among three positions of coil pieces in corresponding coil piece group to be differently between the first and second coil piece groups, the upper coil pieces of the first and fourth parallel circuits are placed in the 3rd, 4th, 7th, 10th, and 15th positions from the pole center, the lower coil pieces of the first and fourth parallel circuits are placed in the 1st, 6th, 9th, 10th, and 13th positions from the pole center, the upper and lower coil pieces (15, 16) of the second and fifth parallel circuits are placed in the 2nd, 5th, 8th, 11th, and 14th positions from the pole center, the upper coil pieces of the third and sixth parallel circuits are placed in the 1st, 6th, 9th, 12th, and 13th positions from the pole center, and the lower coil pieces of the third and sixth parallel circuits are placed in the 3rd, 4th, 7th, 12th, and 15th positions from the pole center.