A Ga2O3 crystal film is epitaxially grown on a Ga2O3 crystal substrate using an MBE method, while controlling the n-type conductivity with high accuracy. Provided is a method for producing a Ga2O3 crystal film, wherein a conductive Ga2O3 crystal film is formed by epitaxial growth using an MBE method. This method for producing a Ga2O3 crystal film comprises a step wherein a Ga2O3 single crystal film containing Sn is grown by producing a Ga vapor and an Sn vapor and supplying the Ga vapor and the Sn vapor to the surface of a Ga2O3 crystal substrate as molecular beams. The Sn vapor is produced by heating Sn oxide that is filled in a cell of an MBE apparatus.