A coil component includes: first and second magnetic cores having first and second flat plate portions; a winding having a hollow core portion; first and second heat dissipation metal plates having first and second heat dissipation plane and first and second heat conduction portions, at least either one of the first and second flat plate portions has a middle leg, the middle leg is inserted into the hollow core portion of a winding, and the first magnetic core and the second magnetic core are combined in such a way that the first flat plate portion and the second flat plate portion face each other, the first heat dissipation plane portion is closely attached to the first flat plate portion and the second heat dissipation plane portion is closely attached to the second flat plate portion, the first heat conduction portion is connected to the second heat conduction portion.