NOVELTY - The sulfur-removal installation of sulfide-containing gas has gas-liquid contact column (2), absorption liquid tank (3) and circulation unit (4) having liquid supply path (41) and return path (42). Tank (3) has a return liquid chamber (a), absorption liquid supply chamber (31) and partition (32). Chamber (a) introduces gas absorption liquid, which absorbed sulfide-containing gas. Chamber (32) introduces absorption liquid overflowed from chamber (a). Absorption liquid is fed into column (2) by potential energy possessed by absorption liquid in chamber (31).    USE - For removing sulfur from sulfide-containing gas, such as sewage gas produced during methane fermentation of organic substance, such as biological sludge.    ADVANTAGE - The installation number of pumps used for circulating absorption liquid between gas-liquid contact column and absorption liquid tank is reduced.    DETAILED DESCRIPTION - The sulfur-removal installation of sulfide-containing gas has a gas-liquid contact column (2) comprising a water-sprinkling unit (22) and an absorption chamber (21), into which sulfide containing gas is introduced, an absorption liquid tank (3) for holding absorption liquid, and a circulation unit (4). The unit (22) carries out water sprinkling of absorption liquid, which absorbs sulfide-containing gas in absorption chamber. The unit (4) has liquid supply path (41) and return path (42) for respectively connecting column (2) and tank (3). Tank (3) has a return liquid chamber connected to one end of return path, absorption liquid supply chamber (31) connected to one end of path (41), and a partition (32) for dividing return liquid chamber and chamber (31). The return liquid chamber introduces gas absorption liquid, which absorbed sulfide-containing gas. The chamber (32) introduces absorption liquid overflowed from return liquid chamber. The absorption liquid is introduced into column (2) by potential energy possessed by absorption liquid in chamber (31).    DESCRIPTION OF DRAWING(S) - The figure shows the model of sulfur-removal installation.    Sulfur-removal installation (1)    Gas-liquid contact column (2)    Absorption liquid tank (3)    Circulation unit (4)    Absorption chamber (21)    Water sprinkling unit (22)    Absorption liquid feed chamber (31)    Partition (32)    Liquid supply path (41)    Return path (42)