PROBLEM TO BE SOLVED: To improve the detection accuracy in relation to a method for determining the reaping time. SOLUTION: This method for determining the reaping time uses an apparatus for determining the reaping time comprising a spectroscope body and a detecting part unit. The determination is carried out by irradiating raw unhulled rice in a sample container attached to an attaching part of the detecting part unit with light within the range of the visible light region to the near infrared region, measuring the moisture value and the content of green unhulled rice of the sample while obtaining the absorbance at a prescribed wavelength in each region and determining which one of early harvesting, proper harvesting and late cutting the reaping time for grains falls under.
