Etching method and substrate processing system

In an etching method for removing a processing target layer formed on a substrate for manufacturing electronic devices, a first break-through process of removing an oxide film formed on a surface of the processing target layer is performed, and a first main etching process of etching the processing target layer is performed after the first break-through process. Then, a second break-through process of removing the oxide film exposed after the first main etching process is performed, and a second main etching process of etching the processing target layer is performed after the second break-through process.