The in-vivo image acquiring apparatus includes an imaging unit which captures an inside of a subject, a transmission processing unit which wirelessly transmits the image information captured by the imaging unit, a power supply unit which supplies driving power for each unit of the apparatus, and a switching unit which detects an external input and switches a supply state of the driving power from the power supply unit. The apparatus also includes a mode setting unit which sets predetermined operation modes based on information of the external input which is input to the switching unit, and a control unit which controls the operation of each unit of the apparatus according to the operation mode set by the mode setting unit.