A laminated coil substrate includes a printed wiring board including a resin substrate, a first conductor layer on first surface of the substrate and including coils, and a second conductor layer formed on second surface of the substrate on the opposite side and including coils. The printed wiring board includes first, second and third coil substrates that are folded such that the second surface of the substrate in the first and second coil substrates oppose each other and that the first surface of the substrate in the second and third coil substrates oppose each other, the second conductor layer of the printed wiring board includes connection wire on the second surface of the substrate and connecting the first and second coil substrates, and the first conductor layer of the printed wiring board includes connection wire on the first surface of the substrate and connecting the second and third coil substrates.