PURPOSE: A grain refrigerator capable of preventing the degeneration of grains is provided to prevent the moisture inside a cooler from passing through the cooler, by forming a non-permeable layer. CONSTITUTION: A grain refrigerator(200) comprises the following: a cooler(207) installed in the inside of a grain storage space; and an evaporator installed in the inside of the cooler. A non-permeable layer(217) is formed in the inner surface of the cooler, with a synthetic resin or a metal material by sintering.본 발명은 곡물 저장부에 냉각기가 설치된 곡물 냉장고에 관한 것으로, 냉각기의 내부면에 불투층을 형성하도록 하여 냉각기 내부의 습기가 냉각기를 통과하지 않도록 함으로써 곡물의 변질을 방지하도록 하기 위한 것이다.