A rotary machine stator comprising: - a stator core in a cylindrical shape, the stator core including a slot, teeth and a slot opening between top edges, wherein the top edges extend from the end of the teeth in the circumferential direction; - an insulating film formed in a cylindrical shape to be in close contact with an inner surface of the slot, the insulating film including a gate on both ends in a circumferential direction that is bent inside of the slot to form a film opening, the insulating film configured to be inserted in the slot such that a film axial direction end of the insulating film protrudes from an axial direction end of the stator core; and - an insulator in a ring shape attached to both ends of the stator core in an axial direction, the insulator including an insulator slot and an insulator opening between insulator edges, formed to be substantially identical in shape with the slot and the slot opening between the top edges of the stator core, respectively, wherein - a width of the film opening is equal to or larger than a width of the slot opening, and that - the insulator edges are provided with a lock having a lock claw located inside of the insulator slot circumferentially away from the insulator opening and a lock groove formed between the lock claw and the insulator edge, the claw further having a gap which is shifted from the end of the insulator edge at the insulator opening side toward a side opposite of the insulator opening by the thickness of the insulating film or more. such that the insulating film is located in the groove and the gate of the insulating film is located in a space formed by the gap - a stator core in a cylindrical shape, the stator core including a slot, teeth and a slot opening between top edges, wherein the top edges extend from the end of the teeth in the circumferential direction; - an insulating film formed in a cylindrical shape to be in close contact with an inner surface of the slot, the insulating film including a gate on both ends in a circumferential direction that is bent inside of the slot to form a film opening, the insulating film configured to be inserted in the slot such that a film axial direction end of the insulating film protrudes from an axial direction end of the stator core; and - an insulator in a ring shape attached to both ends of the stator core in an axial direction, the insulator including an insulator slot and an insulator opening between insulator edges, formed to be substantially identical in shape with the slot and the slot opening between the top edges of the stator core, respectively, wherein - a width of the film opening is equal to or larger than a width of the slot opening, and that - the insulator edges are provided with a lock having a lock claw located inside of the insulator slot circumferentially away from the insulator opening and a lock groove formed between the lock claw and the insulator edge, the claw further having a gap which is shifted from the end of the insulator edge at the insulator opening side toward a side opposite of the insulator opening by the thickness of the insulating film or more. such that the insulating film is located in the groove and the gate of the insulating film is located in a space formed by the gap