NOVELTY - The reactor has a case (4) that includes bottom plate portion (40) and side wall portion (41) that surrounds the periphery of assembly (10). A fastening base unit (415) fixes a portion of terminal metal fitting (8) by a fastening element (419). A rocking suppressing unit (416) controls the rocking of terminal metal fitting during clamping the fastening element. A positioning unit (417) locates the terminal metal fitting that are formed integrally with side wall portion by insulating resin. A latching unit (86) is formed from a portion of belt-shaped material, and is latched by unit (416).    USE - Reactor used for converter (claimed) such as direct current-direct current converter of air conditioning machine mounted on vehicle such as hybrid vehicle, plug-in hybrid motor vehicle and fuel cell electric vehicle.    ADVANTAGE - Since terminal fitting is less prone to oscillate and is highly stable due to rocking suppressing unit and latching unit, the bolt can be easier to fasten and workability is improved. The reactor can be assembled easily. The filling space of the sealing resin is reduced when fastening base unit is smaller, so that injection time and cure time of the sealing resin is shortened, and filling operativity can be improved. Hence usage-amount of the sealing resin is reduced and cost can be reduced. Since packing of sealing resin is provided between the base plate unit and the side wall unit, the non-hardened resin leaks from the clearance gap between the base plate unit and the side wall unit can be prevented. The heat dissipation and insulation can be improved if resin containing the ceramic filler in the side wall portion.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a converter; and    (2) a power converter device.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of reactor.    Case (4)    Metal fitting (8)    Assembly (10)    Bottom plate portion of case (40)    Side wall portion of case (41)    Latching unit (86)    Fastening base unit (415)    Rocking suppressing unit (416)    Positioning unit (417)    Fastening element (419)