The present invention relates to a grain refrigerator including a housing having a grain storage space formed thereon to discharge grains stored therein, a fixing rod located at the center of the inside lower portion of the housing, dew condensation prevention means fixed to the fixing rod, a support plate located on a top periphery of the dew condensation prevention means, an evaporator disposed on the support plate to generate cool air, and a cooling tube disposed on a top periphery of the support plate on the outside of the evaporator to cool the grains, wherein a first pipe and a second pipe connected to the lower portion of the evaporator pass through a through hole of the support plate and a first drain hole of the dew condensation prevention means and are thus exposed to the outside of the housing.