Method of dry etching oxide semiconductor film

A method of dry etching an oxide semiconductor film including In, Ga, and Zn, which comprises performing etching in a gas atmosphere containing a halogen-based gas, wherein a reaction pressure during the etching is within a range of 0.6 Pa or more and 2.4 Pa or less, and wherein a bias RF power is applied at a density of 0.02 W/cm2 or more to a substrate side during the etching.