The invention is a method for detecting float or peel of semiconductor chips arranged in X and Y axes directions diced and bonded to a dicing tape on a stage. The method includes detecting float or peel of the semiconductor chips in a respective horizontal or longitudinal row arranged in the X or Y axis direction; moving the stage in the X axis direction, the Y axis direction, a Z axis direction, and a rotational direction around the Z axis for aligning the stage with a position detection unit for detecting positions of the semiconductor chips in the X axis direction and the Y axis direction; detecting the positions of abnormal semiconductor chips in the respective horizontal or longitudinal row that includes said abnormal semiconductor chips; and specifying the positions of said abnormal semiconductor chips on the X-Y axes.