Provided is a marking system, comprising: a marker which is positioned to transect a wall part of a luminal organ an applicator which further comprises an insertion which is capable of insertion into the wall part, and wherein at least a portion of the marker is housed and a pointer device, further comprising an introduction part which is formed long and flexible and wherethrough the insertion is capable of penetrating, and a light source part which is positioned within the introduction part. At least a portion of the introduction part is light occlusive on the outer circumference surface, suppressing leakage of light emitted from the light source part to the outside of the introduction part.
