A living body pressing clip (1A) comprises a clip body (10) and a cylindrical member (20) that is slidably attached to the clip body (10) and fastens the clip body (10). The clip body (10) is provided with arm parts (11) that hold a mucosal tissue in a luminal organ when fastened by the cylindrical member (20). The cylindrical member (20) is provided with a pressing part (22) that presses the mucosa in a direction of thinning the thickness (D) of the mucosa in the state where the cylindrical member (20) fastens the clip body (10) so that the clip body (10) holds the mucosal tissue in the luminal organ. The pressing part (22) contains a fluorescent dye capable of emitting a red or near-infrared light when irradiated with an exciting light. By using this living body pressing clip (1A), a light-emitting site of a light-emitting marker attached to a mucosal tissue in a luminal organ can be confirmed with a good visibility, even in the case of observing from outside the luminal organ.
