A magnetic device includes a stacked body including a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a first insulating layer which covers side surfaces of the stacked body; and a radiator located outside the first insulating layer with respect to the stacked body, in which a distance between the stacked body and the radiator differs depending on a position of the stacked body in a stacking direction.