Abstract: A pattern forming method is provided. The pattern forming method includes a first step of forming a resist pattern including a lactone group-containing skeleton above an etched layer provided on a substrate; a second step of performing plasma processing using a hydrogen-containing gas to lower a glass transition temperature or a softening point of the resist pattern; and a third step of transferring the resist pattern after the plasma processing to the etched layer by etching, and forming the pattern of the etched layer.