A method of fabricating a flash memory includes providing a fin structure. The fin structure includes a floating gate material, an oxide layer and a semiconductive layer. An insulating layer is disposed at two sides of the fin structure. Then, a dielectric layer conformally covers the floating gate material and insulating layer. Later, a patterned first mask layer, a patterned second mask layer, and a control gate are stacked on the dielectric layer from bottom to top. The control gate crosses at least one fin structure. Next, at least one isotropic etching step is performed to entirely remove the exposed dielectric layer.