To obtain a stator for dynamo-electric machine, the winding of which is improved in the ease of assembly.

In the stator of a generator-motor, the three-phase winding 10 thereof is formed by electrically connecting winding portions 11 to 13 in respective phases, which include straight portions 11a to 13a inserted into slots and having rectangular cross sections and interconnecting portions 11b to 13b connecting together the ends of the adjacent straight portions 11a to 13a and having rectangular cross sections. The winding portions 11 to 13 are provided with a plurality of conductor piece units, which are wound in spiral shape at right angles on the four corners and include the straight portions 11a to 13a and the interconnecting portions 11b to 13b. The plurality of the conductor piece units are laminated, so that the interconnecting portions 11b to 13b of one of any two adjacent conductor piece units are positioned between the interconnecting portions 11b to 13b of the other, and are further linked to each other in the circumferential direction.