PURPOSE: To provide a process for the aging of a vegetable food or animal food.

CONSTITUTION: The aging process for a vegetable food such as wheat flour, cereal and nut or an animal food such as fish meat or cattle meat comprises the hydration of the food and the storage and aging of the hydrated food in a non-freezing temperature range below 0°C optionally in combination with the irradiation treatment with far infrared ray having a specific wavelength and optionally the drying treatment of the product. The aged food is prepared by the above aging treatment of a food. The obtained aged food has remarkable aging effect to get extremely excellent luster, palatability, taste and flavor of the food compared with conventional food and the aging effect can be achieved within an extremely short period.