A relative position information acquiring section acquires relative position information, in relation to an insertion subject, of a portion of an inserting section which becomes a position detection object. An image acquisition position calculating section calculates an image acquisition position that is at least one of an image acquisition region, a part of the image acquisition region and a point in the image acquisition region, by use of the relative position and shape information of the insertion subject. A display calculating section sets a display format on the basis of weighting information of the image acquisition position calculated on the basis of a weighting index parameter. An output section outputs the display format and the image acquisition position.
