To increase efficiency of treating processes such as washing, heat treating and the like of food by bringing them to be continuous.

A first jet device 2 which jets up water in the upward direction along one end wall 11 of a water tank 1 is fitted inside the water tank 1 the upper surface of which is open, the take-in end of a net conveyor 3 is installed in the vicinity of the upper end edge of the other end wall 11, foods in the water tank 1 are sent onto the net conveyor 3 by the first jet device 2 and the foods are conveyed by the net conveyor 3 and taken out from the take out end of the net conveyor 3.