A method of manufacturing a device includes: a laser beam-machined groove forming step of irradiating a wafer with a laser beam from the back side of the wafer along planned dividing lines so as to form laser beam-machined grooves along the planned dividing lines; an etching step of etching a back-side surface of the wafer having been subjected to the laser beam-machined groove forming step, so as to remove denatured layers formed at processed surfaces of the laser beam-machined grooves; an adhesive film attaching step of attaching an adhesive film to the back-side surface of the wafer having been subjected to the etching step, and adhering the adhesive film side of the wafer to a surface of a dicing tape; and an adhesive film rupturing step of expanding the dicing tape so as to rupture the adhesive film along individual devices.