A method of etching an insulation layer on an object to be processed in a process chamber in which an upper electrode and a lower electrode are placed facing each other, includes supplying a process gas that includes fluorocarbon gas and silicon tetrafluoride (SiF4) gas into the process chamber; applying high frequency power to at least one of the upper electrode and the lower electrode, to generate plasma; and etching the insulation layer by the generated plasma via a mask.