A coil electric conductor has an insulating substrate, a first conductive
layer, and a second conductive layer. The first conductive layer is
formed at a depression provided on a face of the insulating substrate.
The second conductive layer is formed on the first conductive layer with
the first conductive layer interposed between the second conductive layer
and the insulating substrate. This construction realizes a coil electric
conductor having a highly precisely uniformized cross-sectional shape.