A biopsy tissue sampling treatment instrument includes a stem portion having a predetermined length sufficient to puncture living tissue a puncturing portion formed at a distal end of the stem portion and having a protruding surface portion expanding rearward along a puncture direction of the stem portion a tissue holding surface provided on a rear side of the protruding surface portion in the puncturing portion and having an area large enough to hold the living tissue a stopper member provided at a rear end of the stem portion and having an abutting portion capable of abutting against the living tissue punctured by the stem portion and an operating member provided on the stopper member and configured to hold the stem portion to the living tissue, allowing the stem portion to puncture the living tissue. Consequently, the biopsy tissue sampling treatment instrument increases holding capacity for the living tissue to be extracted, allows living tissue to be extracted in sufficient sampling quantities, and makes it easy to take samples of living tissue at an intended depth in tissue.
