A floatation-volume adequacy determining system including a receiving unit; an image processing unit; an adequacy determining unit; and a display unit. The receiving unit receives an actual image that is taken by a capsule medical apparatus that is floating in a liquid in the direction toward the liquid level. The image processing unit generates a determination reference image that represents an adequate range of a floatation volume of the capsule medical apparatus adjusted to the actual image that is taken by the capsule medical apparatus. An adequacy determining unit compares the determination reference image and the actual image with each other and determines whether the floatation volume of the capsule medical apparatus is adequate. The display unit displays a result of determining whether the floatation volume of the capsule medical apparatus is adequate.