Provided is a small and simple automatic water quality surveillance apparatus that can automatically sense toxic substances, oil, mold, or the like contained in raw water. The apparatus includes an odor-sensing water tank through which the raw water circulates. The tank further includes an odor sensor sensing an odor, such as an oily odor, a mold odor, and so on. Upon having sensed the toxic substances, oil, mold, or the like, an alarm is automatically issued thereby.
