PURPOSE: To dissolve and remove harmful components into a solvent to make the harmful waste gas generated in soldering work into a pollution-free and clean state and to release the same into the atmosphere by passing said gas through the specific solvent.

CONSTITUTION: A solvent ("Daifron") 10 and water 9 are put into a tank 6, and a pipe 5 is inserted into the tank 6 down to the neighborhood of the bottom thereof. A Venturi type evacuating device 12 is mounted to the tank 6 and the inside of the tank 6 is evacuated by the compressed air which is fed through a compressed air hose 11. A soldering iron 4 is placed under the smoke collecting port 2 at the forward end of the hose 1 connected to the pipe 5 in this case, and the waste soldering gas 3 contg. harmful components generated in soldering is sucked into the hose and is released as bubbles 8 into the solvent 10 from the end of the pipe 5 to dissolve and the harmful components in the solvent 10 are absorbed. The waste gas 3 is released in a clean and pollution-free from an evacuation hose 13 to prevent the contamination of the working environment.