Provided is an in-vivo image capturing system including a capsule casing, an analyzing unit, and a warning unit. The capsule casing is insertable into a body of a subject from an oral cavity and it includes an imaging optical system which may obtain images only in one end direction. The analyzing unit analyzes the image components within the oral cavity obtained by the imaging optical system. The warning unit issues a warning to a user about the direction of the capsule casing based on the analytical result by the analyzing unit.
