An object of the present invention is to provide a n-type semiconductor element having improved n-type semiconductor characteristics and excellent stability with a convenient process, where the n-type semiconductor element includes: a substrate; a source electrode, a drain electrode, and a gate electrode; a semiconductor layer in contact with the source electrode and the drain electrode; a gate insulating layer for insulating the semiconductor layer from the gate electrode; and a second insulating layer positioned on the opposite side of the semiconductor layer from the gate insulating layer and in contact with the semiconductor layer, where the semiconductor layer contains nanocarbon, and the second insulating layer contains (a) a compound with an ionization potential in vacuum of 7.0 eV or less, and (b) a polymer.