A method of forming fine patterns of a semiconductor device comprises forming sacrificial film patterns of a line type in a cell region of a semiconductor substrate and, at the same time, forming pad patterns in a peripheral region of the semiconductor substrate, forming a spacer on sidewalls of each of the sacrificial film patterns and the pad patterns, forming a gap-fill layer on sidewalls of the spacers to thereby form line and space patterns, including the sacrificial film patterns and the gap-fill layers, in the cell region, and separating the line and space patterns of the cell region at regular intervals and, at the same time, etching the pad patterns of the peripheral region to thereby form specific patterns in the peripheral region.