PURPOSE: To save labor and time by dicing a wafer as reared with a marking film to separate chips with cuts of the marking film.

CONSTITUTION: A wafer 20 with a plurality of built-in semiconductor devices separated into chips 10 is reared with a marking-equipped marking film 30. Next, with the wafer 20 kept by the adhesive face 41 of a keeping sheet 40 via this marking film 30, this is diced from its front side, and chips 10 with the marking film 30 adhered are peeled off from the adhesive face 41 of the keeping sheet 40 to separate from the wafer 20. During wafer dicing, it is advantageous to cut the wafer 20 by means of a thin diamond cutter to separate into chips 10 reared with cuts of the marking film 30; therefore, thinning the marking film is desired. This process can save labor and time.