PURPOSE: To provide the subject method for long-term preservation of harvested mandarin oranges with the outbreak of their disease injuries suppressed and their high freshness retained.

CONSTITUTION: A storage chamber containing mandarin oranges is continuously fed with low-temperature and low-humidity air while continuously exhausting the resultant excess air in the chamber to the outside; concurrently, the storage chamber is indirectly cooled by the above low-temperature, and low-humidity air and another cooling means to store the mandarin oranges at low temperatures; during this low-temperature storage, when the humidity in the chamber rises above a set value, low-temperature and low-humidity air is introduced into the storage chamber independently of the above continuously fed air to regulate the humidity inside the chamber.