PURPOSE: To maintain freshness of food by a preserving solution in high yield by spraying the preserving solution and a carbon dioxide gas upon a fine mesh to give a finely granular preserving solution and uniformly attaching the fine granules to the food in a chamber.

CONSTITUTION: A high pressure carbon dioxide gas is blended with a preserving solution such as NH3 or ethanol and sprayed from a nozzle upon a fine mesh. Consequently, the preserving solution in a granular state of large particle size or in a state close to fluid flow is forcibly made into ultrafine particle state by the fine mesh. The fine mesh having about 0.5-1mm may ba used and by piling plural fine meshes, the preserving solution is efficiently converted into the ultrafine particles and a mist atmosphere in an ultrafine particle state can be produced in a chamber. Therefore, the preserving solution is uniformly and evenly attached to foods and raw foods such as fresh fishes. By the above- mentioned method, the amount of the preserving solution dripped is extremely reduced and yield can be improved.