An object is to provide a cold storage in which a cooling box is attached to a bottom wall of a thermal insulation box member without any trouble, cold air circulation is constituted in such a manner that cold air which has exchanged heat with a cooler is discharged into a storage chamber by an air blower via a cold air discharge port, and sucked into a cooling chamber via a cold air suction port, and the inside of the storage chamber can be cooled. A mechanical chamber is constituted under the storage chamber constituted in the thermal insulation box member, and the cold storage comprises: a cooling unit in which a cooler and a blower contained in the cooling chamber constituted in the cooling box, a compressor, a condenser and the like are arranged and integrated; and the cold air discharge port and the cold air suction port which are formed in the bottom wall of the thermal insulation box member constituting a ceiling of the mechanical chamber and which connect the inside of the storage chamber to that of the mechanical chamber. The compressor, condenser and the like are disposed on an attachment base, the cooling box is disposed on the attachment base in such a manner as to be movable to upper/lower positions, and the only cooling box is pushed up in a direction of the bottom wall.