NOVELTY - A metal-oxide film (40) contains indium, zinc, and gallium and/or aluminum, and a hydroxyl group. The main metallic elements of the film surface (40B) at the side of substrate are indium and zinc. The molar ratio of zinc and indium is 0.5-2. The molar ratio of the sum total of gallium and aluminum and the sum total of indium and zinc is 0-0.125. The main metallic elements of the film surface (40T) of the substrate side and the other side are indium and zinc, and gallium and/or aluminum.    USE - Metal-oxide film is used for semiconductor active layers of semiconductor devices e.g. bottom-gate-type thin-film transistor (both claimed) used as switching element in LCDs, electroluminescent display devices, and other active-matrix type flat panel displays. Can also be used for thin film diodes, solar cells, and thermoelectric conversion devices.    ADVANTAGE - The metal-oxide film can be manufactured by a low-temperature liquid-phase process. The metal-oxide film has characteristics favorable as semiconductor active layer. The metal-oxide film provides thin-film transistors having excellent switching characteristics, such as high ON/OFF electric current ratio.    DETAILED DESCRIPTION - A metal-oxide film of amorphous structure is formed on a glass substrate (10), and contains indium, zinc, and gallium and/or aluminum, and a hydroxyl group. The composition of film surface at the side of substrate, and the composition of film surface at the substrate side and other side have a composition distribution. The main metallic elements of the film surface at the side of substrate are indium and zinc. The molar ratio of zinc and indium is 0.5-2. The molar ratio of the sum total of gallium and aluminum and the sum total of indium and zinc is 0-0.125. The main metallic elements of the film surface of the substrate side and the other side are indium and zinc, and gallium and/or aluminum. The molar ratio of zinc and indium is 0.5-2. The molar ratio of the sum total of gallium and aluminum and the sum total of indium and zinc is 0.375 or more. INDEPENDENT CLAIMS are included for the following:    (1) manufacture of metal-oxide film; and    (2) semiconductor device (1).    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the semiconductor device.    Semiconductor device (1)    Substrate (10)    Metal-oxide film (40)    Film surface at side of substrate (40B)    Film surface of substrate side and other side (40T)