[en] An actual condition of technique of safety handling and monitoring of tritium in the laboratory which treated a great quantity of tritium in relation to nuclear fusion, was described. With respect to the technique of safety handling of tritium, an actual condition of the technique in the U.S.A. which had wide experience in treating a great quantity of ³H was mainly introduced, and it was helpful to a safety measure and a reduction of tritium effluence. Glovebox, hood, and other component machinery and tools for treating ³H were also introduced briefly. As a monitoring technique, monitoring of indoor air and air exhaust by ionization chamber-type monitor for continuous monitoring of a great quantity of gaseous tritium was mentioned. Next, monitoring of a room, the surfaces of equipments, and draining, internal exposure of the individual, and monitoring of the environment were introduced. (Kanao, N.)