Abstract: A method for manufacturing a stator of a rotary electric machine, the stator including cassette coils each formed of a flat rectangular conductor wire wound in a distributed winding form and a stator core including slots in which the cassette coils are inserted, includes the steps of: assembling a plurality of adjacent in-phase cassette coils to form a set of assembled coils; winding an insulation sheet cut in a predetermined shape around an outer periphery of a proximity section of the assembled coils in which the cassette coils are located close to each other; fixing end portions of the wound insulation sheet to each other; and overlapping sets of the assembled coils in a circumferential direction of the stator core, each set being bound together by the insulation sheet having the fixed end portions, and inserting the assembled coils in the slots.