A non-volatile memory structure includes a substrate, a tunnel dielectric layer on the substrate, and several separate gate structures on the substrate. The gate structures are disposed within an array region of the substrate. Each gate structure includes a floating gate and a control gate on the floating gate. A first dielectric layer is formed above the substrate and covers the top surface of the tunnel dielectric layer. The first dielectric layer also covers the side surfaces and the top surface of each gate structure. Gaps between portions of the first dielectric layer on the side surfaces of two adjacent gate structures are fully filled with the air to form air gaps. Several insulating blocks are formed on the first dielectric layer, and they correspond to the gate structures. A second dielectric layer is formed on the insulating blocks and covers the insulating blocks and the air gaps.