In a method for manufacturing a stator of a motor, when an angular line is used to increase the occupancy rate of line members for coil pieces inserted into slots, not-slot-inserted parts project from a stator core. This results in enlarging the size of a stator, and damaging coatings via interference between a coil piece and other parts. In order to solve these problems, an angular line is first wound a predetermined times. Then, slot-inserted parts (a coil side) are separately clamped, and one of them is rotated by 180 degrees in a direction perpendicular to the winding direction, so that twisted parts are formed on coil ends. The coil sides are sequentially inserted into predetermined slots while maintaining respective twisted parts substantially parallel to each other, until a stator is completed.