A gastrointestinal tract examining apparatus (5, 5C, 5D, 5G-K) comprising: a capsular endoscope (3, 3C, 3D, 3G-K) adapted to examine the gastrointestinal tract comprising an illuminating portion and an image pick-up element; a flexible tube member which is longer than the gastrointestinal tract from a mouth to a stomach of a patient; one flexible string member or a plurality of flexible string members (6, 6a, 6b) which are adapted to be inserted into the tube member and a connecting portion which is arranged to the capsular endoscope (3, 3C, 3D, 3G-K), wherein the tube member is adapted to be separatively connected to the capsular endoscope (3, 3C, 3D, 3G-K) by detachably connecting the string member (6, 6a, 6b) to the connecting portion characterized in that each of the string members has at least twice the length of the tube member; and the capsular endoscope (3, 3C, 3D, 3G-K) further comprises a radio transmitting portion adapted for transmitting by radio an image signal picked up by the image pick-up element to an extracorporeal unit and the connecting portion comprises a through-hole or a plurality of through-holes (29, 29a, 29b, 77a, 77b) which are provided to the capsular endoscope (3, 3C, 3D, 3G-K) and are arranged at apart positions, and the capsular endoscope (3, 3C, 3D, 3G-K) is detachably connected to the tube member by the one or more of the string members (6, 6a, 6b) wherein each string member is adapted to be inserted and folded through one of the through-holes (29, 29a, 29b, 77a, 77b) so that in each through-hole is inserted one string member, and in that the examining apparatus is adapted to change a direction of field of view of the image pick-up element by towing and loosening the one or more string members (6, 6a, 6b) pulled out from a proximal end of the tube member. a capsular endoscope (3, 3C, 3D, 3G-K) adapted to examine the gastrointestinal tract comprising an illuminating portion and an image pick-up element; a flexible tube member which is longer than the gastrointestinal tract from a mouth to a stomach of a patient; one flexible string member or a plurality of flexible string members (6, 6a, 6b) which are adapted to be inserted into the tube member and a connecting portion which is arranged to the capsular endoscope (3, 3C, 3D, 3G-K), wherein the tube member is adapted to be separatively connected to the capsular endoscope (3, 3C, 3D, 3G-K) by detachably connecting the string member (6, 6a, 6b) to the connecting portion characterized in that each of the string members has at least twice the length of the tube member; and the capsular endoscope (3, 3C, 3D, 3G-K) further comprises a radio transmitting portion adapted for transmitting by radio an image signal picked up by the image pick-up element to an extracorporeal unit and the connecting portion comprises a through-hole or a plurality of through-holes (29, 29a, 29b, 77a, 77b) which are provided to the capsular endoscope (3, 3C, 3D, 3G-K) and are arranged at apart positions, and the capsular endoscope (3, 3C, 3D, 3G-K) is detachably connected to the tube member by the one or more of the string members (6, 6a, 6b) wherein each string member is adapted to be inserted and folded through one of the through-holes (29, 29a, 29b, 77a, 77b) so that in each through-hole is inserted one string member, and in that the examining apparatus is adapted to change a direction of field of view of the image pick-up element by towing and loosening the one or more string members (6, 6a, 6b) pulled out from a proximal end of the tube member.