Oxide film and process for producing same

This oxide film of an embodiment is a film which comprises an oxide comprising both silver (Ag) and nickel (Ni) (and which can contain unavoidable impurities). This oxide film shows no distinct diffraction peak in XRD (X-ray diffraction) analysis, as seen from the charts that show the results of XRD analysis of a first oxide film in fig. 3 and a second oxide film. This oxide film is an arrangement of fine crystals, an amorphous film containing fine crystals, or an amorphous film and has p-type conductivity. This oxide film can have high p-type conductivity while having a wider band gap than conventional oxide films. Since this oxide film is an arrangement of fine crystals, an amorphous film containing fine crystals, or an amorphous film, as stated above, formation of the film on a large substrate is easy. Consequently, this oxide film is also suitable for industrial production.