To provide a device and an inner plug with which the external form of an adherent body, formed by an adhesive substance adhering to the surface of an adherend, can be flexibly changed while avoiding size increases in the dimension orthogonal to the adhesive substance extrusion direction. A device for holding a fluid adhesive substance and for discharging the adhesive substance towards the surface of an adherend is provided with a container section and a discharging section (30). The container section is able to deform so as to cause the adhesive substance inside said container section to flow towards the discharging section (30). The discharging section (30) comprises abutting parts (34) for abutting against the surface of the adherend and multiple gap-forming parts (32) that line up at intervals along the circumferential direction. The multiple gap-forming parts (32) form gaps (C) between mutually adjacent gap-forming parts (32), the gaps having a shape that, when the abutting parts (34) abut against the surface of the adherend, allows the adhesive substance to be discharged so as to spread outward past the abutting parts (34) in the outward discharging direction on the surface of the adherend.