Etching method and plasma processing apparatus

An etching method is performed in a state where a substrate is placed on a substrate support provided in a chamber of a plasma processing apparatus. In the etching method, radio-frequency power is supplied to generate plasma from a gas in the chamber. Subsequently, a negative DC voltage is applied to a lower electrode of the substrate support during the supplying of the radio-frequency power to etch the substrate with positive ions from plasma. Subsequently, the applying of the negative DC voltage to the lower electrode and the supplying of the radio-frequency power are stopped to generate negative ions. Subsequently, a positive DC voltage is applied to the lower electrode in a state where the supply of the radio-frequency power is stopped to supply the negative ions to the substrate.