A method for forming a pattern of a semiconductor device includes: forming a first mask film and a second mask film over an underlying layer; partially etching the first and second mask films using a photoresist mask pattern as an etching mask to form a intermediate mask pattern having a protrusion shape and including first and second mask film layers, over a remaining portion of the first mask film; forming a first spacer at sidewalls of the intermediate mask pattern etching the remaining portion of the first mask film and the first mask film layer of the intermediate mask pattern using the first spacer and the second mask film layer of the intermediate mask pattern as an etching mask to expose the underlying layer and form a mask pattern having first and second mask film layers; forming a second spacer at sidewalls of the mask pattern; and removing the mask pattern to form a symmetrical spacer pattern.