PROBLEM TO BE SOLVED: To provide a technical method for improving productivity by continuously mass-producing GABA-enriched unpolished rice without cracking the unpolished rice.SOLUTION: This method includes ventilating humidification warm air to either one of unhulled rice dried to finish moisture, unhulled rice dried to the half-dry state, or unhulled rice in the raw state to enrich the content of &gamma-aminobutyric acid contained in the unhulled rice, and then drying the unhulled rice to the finish moisture.