Stator and method of producing the same

A stator has a stator core composed of teeth and slots. Segment coils are inserted into the corresponding slots. The segment coil projecting from the slot has an exposed conductor part and a covered conductor part covered with an electrical insulation film. The exposed conductor part is arranged at the distal end side from the covered conductor part of the segment coil. The segment coils are connected together through the exposed conductor parts thereof projecting from the slots. The exposed conductor part has a thickness T2 thinner than a thickness T1 of the covered conductor part. A step part is formed at a position of the stator core side, adjacent to the exposed conductor part of the segment coil. The step part and the covered conductor part are covered with the electrical insulation film continuously from the stator core side of the covered conductor part.