A coil substrate includes insulating layers, and conductive layers laminated on the insulating layers in a plate thickness direction of the insulating layers, respectively. The conductive layers include three or more conductive layers and a set of conductive layers such that the set of conductive layers includes a first outermost conductive layer on one end side in the plate thickness direction and does not include a second outermost conductive layer on the opposite end side in the plate thickness direction and that the set of conductive layers includes coil portions each having a spiral form respectively and aligned in the plate thickness direction.