An alignment method includes: a storage step that images a first workpiece on a chuck table and stores positions of alignment marks corresponding to scheduled division lines and positional relationships of the division lines with the alignment marks; a holding step that holds a second workpiece with the chuck table; a detection step that images positions of the alignment marks on the second workpiece, the positions corresponding to the stored alignment mark positions, and detects the alignment marks of the second workpiece; and an identification step that identifies positions of scheduled division lines of the second workpiece on the basis of the detected positions of the alignment marks of the second workpiece and the stored positional relationships. If one of the alignment marks of the second workpiece cannot be detected at one of the stored alignment mark positions, the detection step detects other adjacent alignment marks.