The invention discloses a method for manufacturing a non-volatile memory. Substrates of a first area and a second area are provided, and a first patterning step is performed on the first area to form a plurality of grid stack structures. Then a side wall for covering each grid stack structure and a first side wall oxide layer of the upper surface are formed, and a protective layer is formed on the first side wall oxide layer. Ion implantation process is performed on the second area, second patterning step is performed on the second area to form a plurality of grid structures in the second area. At last, a second side wall oxide layer for covering the side wall of each grid structure is formed.