A target for sputtering or a tablet for ion plating, an oxide sintered body suitable for obtaining the same and a production method therefor, and a transparent conductive film having low absorption of blue light and low specific resistance, obtained by using the same are provided by an oxide sintered body having indium and gallium as an oxide, characterized in that an In2O3 phase with a bixbyite-type structure forms a major crystal phase, and a GaInO3 phase of a β-Ga2O3-type structure, or GaInO3 phase and a (Ga, In)2O3 phase is finely dispersed therein, as a crystal grain having an average particle diameter of equal to or smaller than 5 μm, and a content of gallium is equal to or higher than 10% by atom and below 25% by atom as atom number ratio of Ga/(In+Ga) or the like.