An air core type reactor unit, includes a first insulating plate which is provided with a first insulating spacer on one side, a first ferromagnetic member metal plate fixed to an insulating plate, two or more air core coils each having an air core part and formed of coil layers with the separation of an air gap, a second insulating plate, which is provided with a second insulating spacer on another side thereof and has a width smaller than an inside diameter of the coil, to incorporate more air into, a second ferromagnetic member metal plate fixed to an insulating plate, and an insulating stick passing through the air core part of the air core coils, wherein the air core coils are arranged in parallel, and held and fixed between the first insulating plate and the second insulating plate through the first insulating spacer and the second insulating spacer.