A stator of a 3-phase electric machine, comprising: a stator core having a plurality of slots; and a stator winding in which a winding has a plurality of segment conductors connected in series to each other, the plurality of segment conductors having a rectangular shaped cross section or circular shaped cross section, wherein the stator winding has a plurality of winding portions (163, 164) for each phase, and wherein the plurality of winding portions (163, 164) are connected in parallel with one another for each phase, and each of the winding portions (163, 164) has a plurality of poles, wherein the plurality of the winding portions (163, 164) has a first winding portion and a second winding portion, and wherein the first winding portion is configured by connecting segment conductors disposed on a first layer and a second layer in series with each other, and the second winding portion is configured by serially connecting segment conductors forming a third layer and a fourth layer, characterized in that the stator winding is configured such that conductors having the same phase as well as having the same current direction are inserted into five slots sequentially disposed along a circumferential direction such that there are three slots for each pole for each winding portion (163, 164) for each phase. the one pole of the first winding portion and the one pole of the second winding portion are disposed to be separated from each other by two slot pitches along the circumferential direction, segment conductors with different phases are commonly inserted into at least any one of the five slots of each of the winding portions, a first layer and a second layer of the first and second slots among the five slots have the same phase along a circumferential direction of the stator core, the first and second layers of the fourth and fifth slots have the same phase which is different from the phase of the first and second layers of the first and second slots, a third layer and a fourth layer of the first and second slots have the same phase, the third and fourth layers of the fourth and fifth slots have the same phase, in each of the first, second, fourth and fifth slots the second layer and the third layer have different phases, and a first layer through a fourth layer of the third slot among the five slots have the same phase. a stator core having a plurality of slots; and a stator winding in which a winding has a plurality of segment conductors connected in series to each other, the plurality of segment conductors having a rectangular shaped cross section or circular shaped cross section, wherein the stator winding has a plurality of winding portions (163, 164) for each phase, and wherein the plurality of winding portions (163, 164) are connected in parallel with one another for each phase, and each of the winding portions (163, 164) has a plurality of poles, wherein the plurality of the winding portions (163, 164) has a first winding portion and a second winding portion, and wherein the first winding portion is configured by connecting segment conductors disposed on a first layer and a second layer in series with each other, and the second winding portion is configured by serially connecting segment conductors forming a third layer and a fourth layer, characterized in that the stator winding is configured such that conductors having the same phase as well as having the same current direction are inserted into five slots sequentially disposed along a circumferential direction such that there are three slots for each pole for each winding portion (163, 164) for each phase. the one pole of the first winding portion and the one pole of the second winding portion are disposed to be separated from each other by two slot pitches along the circumferential direction, segment conductors with different phases are commonly inserted into at least any one of the five slots of each of the winding portions, a first layer and a second layer of the first and second slots among the five slots have the same phase along a circumferential direction of the stator core, the first and second layers of the fourth and fifth slots have the same phase which is different from the phase of the first and second layers of the first and second slots, a third layer and a fourth layer of the first and second slots have the same phase, the third and fourth layers of the fourth and fifth slots have the same phase, in each of the first, second, fourth and fifth slots the second layer and the third layer have different phases, and a first layer through a fourth layer of the third slot among the five slots have the same phase.