PURPOSE: To facilitate the working of a rotor equipped with an oil separator and incorporate the oil separator with a reduced manufacturing cost by a method wherein the oil separator is fixed to an end plate with a predetermined space with respect to the end plate by a simple constitution utilizing an upper end plate at the arranging side of the oil separator.

CONSTITUTION: A protruded part, having a caulking part 39a at the tip end thereof, is fixed to an upper side end plate 34, arranged on the side of an oil separator 38 among end plates 34, 35 arranged on both sides of the laminating direction of a laminated iron sheet core 31, while an oil separator 38 is fixed to the caulking part 39a of said protruded part 39 with a predetermined distance between the upper side end plate 34.