An elongated medical member includes: an insertion portion having a long length, which is provided with a lumen through which an operation treatment instrument for carrying out a predetermined medical action can be penetrated a guide portion for guiding the insertion portion, which is extended from a distal end of the insertion portion and a holding portion provided at a distal end part of the guide portion, the holding portion insertably and removably holding the operation treatment instrument so as to allow the operation treatment instrument to be removed when the operation treatment instrument is pulled toward a proximal end side.
