Rice husk is a waste that can still be used as a source of energy.One way to use it into energy through the gasification method. Gasification is the process of converting solid or liquid fuels into gas fuel by heating in a gasification medium such as air, oxygen and water vapor. Unlike combustion, where the oxidation process occurs perfectly in one step, gasification converts the chemical energy from carbon compounds in biomass into combustible gas in two stages. Gas produced from this process can be more easily utilized compared to biomass. Gasification media is usually called a gasifier or gasification stove. Rice husk was conducted without treatment on updraft gasification stove with 1300 grams of rice husk capacity. Testing is divided into two types of parameters, the parameter is using variations in air velocity and variation of fuel mixture. The first parameter was performed by giving air velocity (V) of 0.7 mps, 0.9 mps and 1.05 mps, while the second parameter was done by giving the fuel mixture in the form of wood char with the percentage of wood char equal to 0%, 25%, 50%, 75% and 100%. The result of the research obtained thermal efficiency value on air velocity variation, the highest value is at V = 0.7 mps that is equal to 27,95%, followed by V = 0.9 mps equal to 24,36% and V = 1.05 mps of 21.98%. In the fuel mixture variation, the highest thermal efficiency was found in the 25% percentage of wood char at 32.09%, followed by 50% by 24.99%, 75% by 21.46% and 100% by 17.11%.