PROBLEM TO BE SOLVED: To reduce the consumption power and treatment time required at the time of radio transmission of image data.SOLUTION: The CPU 50 of a capule endoscope 11 calculates the moving speed in the human body on the basis of the measuring result of an acceleration sensor 59. The CPU 50 compares the absolute value V of the calculated moving speed and a preset threshold values TH1 and TH2 (TH1>TH2) with each other. The CPU 50 outputs a control signal to the driver 53 of a CCD 33 so as to respectively perform photographing in a state that the maximum number of pixels of CCD 33 is Pmax in a case of a relatively high moving speed (V&geTH1), the medium degree number of pixels is Pmid in case of a medium moving speed (TH2&leVTH2)とを比較する。CPU50は、移動速度が比較的速い場合(|V|≧TH1)はCCD33の最高の画素数Pmax、移動速度が中程度の場合(TH2≦|V|
