To reduce a manufacturing cost of molded processed food of a portion- type through the freeze drying of the food by widely shortening drying time of a molded frozen body in a freeze drying chamber in the manufacturing of the molded processed food through freeze drying comprising subliming water in a material under vacuum in the freeze drying chamber.

A plain molded frozen body of a liquid material is placed in a tray having a bottom face of a net or a perforated plate. The frozen body is charged, as it is in a tray, into between a heating shelf and another heating shelf which are arranged with one tray on the top of the other in a freeze drying chamber. The frozen body is freeze dried under conditions of both-side radiational heating and both-side sublimation in the freeze drying chamber.