A method for forming fine patterns of a semiconductor device is disclosed. The method includes forming an etch film on a substrate, forming a protection film on the etch film, forming a hard mask layer on the protection film, and forming a plurality of first mask patterns characterized by a first pitch on the hard mask layer. The method further comprises forming a plurality of second mask patterns, forming hard mask patterns exposing portions of the protection film by etching the hard mask layer using the first and second mask patterns as an etch mask, and removing the first and second mask patterns. The method still further comprises exposing portions of the etch film and forming a plurality of fine patterns characterized by a second pitch equal to half of the first pitch by etching the etch film using at least the hard mask patterns as an etch mask.