The present disclosure provides a coil device that can be reduced in height, has a small installation area of a case, and is excellent in heat dissipation. A coil device according to the present disclosure includes: a device body including a bobbin and a coil unit of a wire wound around the bobbin; a terminal block arranging a lead portion drawn out from a wire of the coil unit thereon; and a case capable of accommodating the device body. The case includes a support arm extending outside the case, and the terminal block is held by the support arm.