There is disclosed a printed inductor 1 having a spiral coil formed outside a cavity 2 by providing an insulating substrate 3 with the cavity 2 extending in a direction orthogonal to that of the thickness of the insulating substrate 3, forming a plurality of mutually independent printed wiring lines 4 on both the top and bottom faces of the insulating substrate 3 facing each other through the cavity 2, and sequentially and continuously connecting terminals of the printed wiring lines 4 on both the top and bottom faces to each other through a plurality of through holes 5.