PROBLEM TO BE SOLVED: To provide a method for generating chlorine dioxide gas by which chlorine dioxide gas can be sustainedly generated for a long period of time, a kit for generating chlorine dioxide gas, and a gel composition.SOLUTION: The method for generating chlorine dioxide gas is method for sustainedly generating chlorine dioxide gas from a gelated composition obtained by mixing chlorite aqueous solution with a gelation activator containing a gas generation regulator, a pH adjustor and a water-absorbing resin. The kit for generating chlorine dioxide gas is composed of an A agent containing chlorite aqueous solution, and a B agent containing gelation activator containing a gas generation regulator, a pH adjuster and a water-absorbing resin, and sustainedly generates chlorine dioxide gas by mixing the A agent and the B agent. The gel composition contains chlorite aqueous solution and a gelation activator containing a gas generation regulator, a pH adjustor and a water- absorbing resin, and sustainedly generates chlorine dioxide gas.SELECTED DRAWING: None
