The superimposition characteristics are improved in an inductance device provided with coils having sections with different numbers of windings. The inductance device includes a ring-shaped coil having n winding section 31 in which the number of windings is n and n+1, magnetic circuit materials mounted within and without the ring of aforementioned coil through which magnetic flux is passed to form a magnetic circuit, and a magnetic gap that blocks either the magnetic flux that was formed so as to surround aforementioned n winding section 31 or the magnetic flux that was formed so as to surround aforementioned n+1 winding section 32.