REACTOR

PROBLEM TO BE SOLVED: To provide a reactor which is excellent in heat radiation performance, is easily fixed to another member with an easy operation, and is composed of a small number of components.SOLUTION: A reactor includes: a reactor body formed by winding a coil 20 around a U shaped core 11; and a cooling plate 30 fixing the reactor body. The U shaped core 11 and the coil 20 are fixed to the cooling plate 30 by fixing members 12. Insulating treatment is performed on a portion of a surface of the cooling plate 30, which faces the coil 20, by an insulation material 33. The coil 20 and the cooling plate 30 are disposed so that a clearance 34 is maintained between a surface of the insulation material 33 of the cooling plate 30 and a surface of the coil for suppressing partial discharging. The fixing members 12 and the cooling plate 30 may be composed of one metal plate P.