NOVELTY - Sulfur type impurities are removed from biogas. The composition, concentration, and heat amount of the obtained gas are adjusted to according to the requirement of town gas. Hydrogen is added and oxygen is converted into water. Reaction heat and moisture content are removed. With the thermal medium heated by the reaction heated, liquefied gas having higher heat amount than the purified gas is heated and vaporized. The heat amount of purified gas added with high-heat-amount liquefied gas is increased to preset value, to obtain town gas.    USE - Manufacture of town gas.    ADVANTAGE - The method enables manufacture of town gas with required heat amount, without requiring power supply for heaters.    DETAILED DESCRIPTION - Sulfur type impurities are removed from biogas to obtained purified high-concentration methane gas. The composition and concentration, and heat amount of the obtained gas are adjusted to according to the requirement of town gas. Hydrogen is added to the purified gas and oxygen remaining in the purified gas is converted into water in a deoxidation catalyst column in which purified gas added with hydrogen in filled and catalyst is supplied. Reaction heat produced during conversion into water is removed, followed by removal of moisture content. With the thermal medium heated by the reaction heated, liquefied gas having higher heat amount than the purified gas is heated and vaporized. The heat amount of purified gas added with high-heat-amount liquefied gas is increased to preset value, to obtain town gas. An INDEPENDENT CLAIM is included for manufacturing apparatus of town gas, consisting of a biogas purifier (2), a component-adjustment unit, and a heat-amount adjustment unit. The component-adjustment unit consists of a hydrogen supplier (13), a deoxidation catalyst column (20), a gas cooler (21) for removing reaction heat, and a moisture-content-removal unit. The heat-amount adjustment unit consists of a high-heat-amount liquefied gas vaporizer and a heat-increment unit.    DESCRIPTION OF DRAWING(S) - The drawing shows an explanatory view of the town-gas manufacturing apparatus. (Drawing includes non-English language text)    Digestion tank (1)    Biogas purifier (2)    Hydrogen supplier (13)    Deoxidation catalyst column (20)    Gas cooler (21)