A dry etching method includes a first step and a second step. The first step includes generating a first plasma from a gas mixture, which includes an oxidation gas and a fluorine containing gas, and performing anisotropic etching with the first plasma on a silicon layer to form a recess in the silicon layer. The second step includes alternately repeating an organic film forming process whereby an organic film is deposited on the inner surface of the recess with a second plasma, and an etching process whereby the recess covered with the organic film is anisotropically etched with the first plasma. When an etching stopper layer is exposed from a part of the bottom surface of the recess formed in the first step, the first step is switched to the second step.