An in-vivo image acquiring apparatus includes an operation control unit which controls a black image acquiring operation, in which the operation control unit controls an imaging unit and an illuminating unit in such a manner the imaging unit conducts an image acquiring operation in a state the illuminating unit does not conduct an illuminating operation. The in-vivo image acquiring apparatus also includes an average calculating unit which calculates the average value of pixel value in a predetermined determining area, and a black image determining unit, which determines whether the image information acquired by the image acquiring operation is the black image by comparing the average value with a predetermined threshold value. The image information determined as the black image by the black image determining unit is transmitted, as the black image information, to an external apparatus by radio.