Insertion amount grasping device

An insertion amount grasping device comprising:

• a first jig fixed to a fixation target in a state where the first jig is positioned against the fixation target, the first jig having a guide through-hole extending toward an application portion in a state where the first jig is fixed to the fixation target;
• an insertion portion configured to be inserted into the guide through-hole such that the insertion portion is introduced toward the application portion in a state where an operator grips the insertion portion;
• and
• a first protruding portion as a protruding portion provided in the insertion portion, the first protruding portion being configured to be inserted into the guide through-hole and cause friction between the first protruding portion and the guide through-hole when a predetermined positional relationship is established between a distal end part of the insertion portion and the application portion along with an introduction operation to introduce the insertion portion toward the application portion.