A refrigerator and a method for keeping food items fresh therein are provided. The refrigerator may include a main body, storage compartments provided in the main body to store food items therein, and irradiation devices that irradiate visible light into the storage compartments. The irradiation devices may switch a wavelength of irradiated light depending on the type of food items stored in the corresponding storage compartment. The refrigerator may also include a sensor that senses whether food items are stored in the storage compartments, and purification devices provided in the compartments to remove ethylene generated by the food items stored in the storage compartments.