To provide a food washing technique enabling food to be washed without causing a foaming due to salt content with high degerming effect while clearing the regulation of Food Sanitation Law by using salt-free electrolysis hypowater as washing water for use in a washing machine.

This food washing technique (method) comprises pouring air foams on food by using the electrolysis hypowater. The hypowater to be used as the washing water W10 is produced by the following process: using a water electrolyzer 5 constructed in such a manner that raw water W is passed through an anode chamber 5a and cathode chamber 5b and an electrolytic aqueous solution D is contained in an intermediate chamber 5c and an electrolytic treatment is then made to feed the electrolytic aqueous solution to the raw water by electrophoresis to obtain acidic electrolysis water in the anode chamber while alkaline electrolysis water in the cathode chamber, the acidic electrolysis water discharged from the anode chamber is mixed with the alkaline electrolysis water from the cathode chamber into the weakly alkaline electrolysis hypowater W7.