Dimethyl Ether (DME, CH3OCH3) is emerging as the most promising alternative fuels in this decades, especially to substitute established fuels such as Liquefied Petroleum Gas (LPG), diesel fuel, and Liquefied Natural Gas (LNG). DME is manufactured from various natural resources such as coal, natural gas, and biomass. This study is aimed to investigate the jet diffusion flame behavior of DME on atmospheric condition by the effect of L/Di ratio of the barrel burner in terms of flame length, flame regime and the stability by means of experimental measurements. A barrel burner designed for this experiment, applying 2 barrels with different length/inner diameter ratio (L/Di). A burner tip with a centered hole with diameter 3.0 mm is functioned as fuel injector. This system worked on unconfined space at atmospheric condition to ensure an environment close to the household cooking condition, where DME is supposed to substitute LPG. The comparison is made to know the behavior of jet diffusion flame of DME to LPG.