A water content evaluation apparatus which evaluates water content of a part of a plant (PT) comprising: a first light source which is configured to radiate a laser reference beam (LS1) of a first wavelength that has a characteristic in which light tends not to be absorbed in water while sequentially scanning across an irradiation area which includes the part of the plant (PT) that is set as an evaluation target and a white or silver background material with high reflectance of visible light and near infrared light that covers a back surface of the part of the plant (PT); the apparatus further comprising a second light source which is configured to radiate a laser measuring beam (LS2) of a second wavelength that has a characteristic in which light tends to be absorbed in water while sequentially scanning across the irradiation area; an identification unit which is configured to identify the part of the plant (PT) that is the evaluation target based on the reflection light of the laser reference beam (LS1) that is reflected on the irradiation area and the reflection light of the laser measuring beam (LS2) that is reflected on the irradiation area; and a water content calculation unit which is configured to calculate water content at all irradiation positions of the part of the plant (PT) that is the evaluation target that is identified by the identification unit based on a reflection light of the laser reference beam (LS1) that is reflected on all irradiation positions of the part of the plant (PT) and a reflection light of the laser measuring beam (LS2) that is reflected on all irradiation positions of the part of the plant (PT). a first light source which is configured to radiate a laser reference beam (LS1) of a first wavelength that has a characteristic in which light tends not to be absorbed in water while sequentially scanning across an irradiation area which includes the part of the plant (PT) that is set as an evaluation target and a white or silver background material with high reflectance of visible light and near infrared light that covers a back surface of the part of the plant (PT); the apparatus further comprising a second light source which is configured to radiate a laser measuring beam (LS2) of a second wavelength that has a characteristic in which light tends to be absorbed in water while sequentially scanning across the irradiation area; an identification unit which is configured to identify the part of the plant (PT) that is the evaluation target based on the reflection light of the laser reference beam (LS1) that is reflected on the irradiation area and the reflection light of the laser measuring beam (LS2) that is reflected on the irradiation area; and a water content calculation unit which is configured to calculate water content at all irradiation positions of the part of the plant (PT) that is the evaluation target that is identified by the identification unit based on a reflection light of the laser reference beam (LS1) that is reflected on all irradiation positions of the part of the plant (PT) and a reflection light of the laser measuring beam (LS2) that is reflected on all irradiation positions of the part of the plant (PT). <EOS>