To effectively wash tableware using a small quantity of detergent by providing a device for heating water fed from the outside to a specified value or more so as to feed and a device for feeding alkaline detergent.

A washing producing device (A) of a tableware washer 1 is provided with a hot water feeder 2 for heating water fed from an outer water feeding source, a controller 3, a tank 4 for storing the water heated to approximately 50-60°C, and a change-over valve 6. After the washing water of the tank 4 or a tank 5 is fed to a washing chamber 9 provided in a washing case 8 of a washing (B) via a pipe 7, it is fed from the pipe 11 via injection nozzles 12a-12d, 14a, 14b and injected to the tableware from the bottom of shelf bodies 13, 14 by a water feed pump 10. The alkaline detergent feeding device 18 adds an alkaline detergent composition formed by adding alkali detergent or enzyme from a detergent feeding port 19 to the washing case 8 by necessary quantity at necessary time.