An etching method for a target object. The target object includes a main surface, grooves formed in the main surface, and an etching target film covering the main surface and surfaces of the grooves. The method includes supplying a first gas into a processing chamber, and supplying a second gas and a high frequency power to generate a plasma of a gas including the second gas in the processing chamber. The first gas contains an oxidizing agent that does not include a hydrogen atom. The second gas contains a compound that includes one or more silicon atoms and one or more fluorine atoms and does not include a hydrogen atom. The etching target film is made of a material that is dry etched by using fluorine, and portions of the etching target film covering the surfaces of the grooves are selectively removed.