PURPOSE: To prevent pollution by sucking and transferring plural kinds of solute materials and solvent materials through piping intercepting the root of pollution with such a simple method as to suck solution material through piping means under noncontact tate as well as to suck solvent material under noncontact state.
CONSTITUTION: In the initializing step, the liquid to be used as solvent is enclosed in a vessel 3, and a 1st open end 9 of a piping 8 is introduced into the vessel 3 to put into the liquid and a 2nd open end 16 of the piping 8 is put above the surface of liquid or powder to be used as solute with a specified distance between. In the solute-supplying step, the inside of the vessel 3 is sucked and decompressed by an air suction means 12 to suck the solute material through the piping 8 to supply it into the solvent in the vessel 3. In the piping washing step, and 2nd open end 16 of the piping 8 is put above the liquid surface of a liquid solvent material in a vessel 24 prepared independently from the solvent material in the vessel 3 with a specified distance between to suck the solvent material by sucking and decompressing the inside of the vessel 3. As a result, the pollution is prevented.