In a heating sterilization device of a cutting tool for agricultural/horticultural crops using combustion of liquefied gas, utilization efficiency of energy obtained by using the liquefied gas of a gas tank is increased, a reliable heating sterilization effect is obtained, and the configuration of the device is simplified. Mixed gas from a liquefied gas cartridge 4, 14 which is assembled in a hand grip 2, 12 is guided to a small metal tube 8, 18 which is arranged in a groove formed on a blade portion 3, 13 as a gas flow path an electric heater wire 9, 19 which is covered with heat storage ceramic material and combustion reaction catalyst 10, 20 are assembled in this gas flow path 8, 18 the combustion reaction catalyst 10, 20 is heated to a temperature, at which a catalytic combustion reaction is initialized, by heating the mixed gas with the electric heater wire 9, 19, the mixed gas is burned flamelessly by the catalyst, and the blade portion 3, 13 is heated and sterilized. Since the blade portion is directly heated by the catalytic combustion reaction caused by the catalyst arranged therein, the thermal transmission effect is enhanced and since the mixed gas is heated by the electric heater wire covered with heat storage ceramic material and the catalyst arranged in the flow path is pre-heated to a combustion initializing temperature, the catalytic combustion reaction occurs reliably, and the blade portion can be kept in a heating sterilization state all the time.
