Abstract: The present invention relates generally to an apparatus and process for liquid immersion natural convection chemical cleaning of industrial and/or household items and in particular to an apparatus and process for cleaning dishware. The invention provides an apparatus for removing foreign substances from a surface through contact with a heated liquid cleaning solution circulating by natural convection. A preferably stainless steel tank holds the cleaning solution and the articles to be cleaned. The tank has at least one electrical heating element preferably energized by a thermostat regulated electrical control system to maintain the temperature of said cleaning solution at a value lying within a predetermined range for a predetermined time period which have both experimentally been proven to provide optimum cleaning results. The cleaning solution comprises a mixture of water and an alkalike non-toxic solution containing no organic solvents.