A tissue collector includes: an elongated sheath; a bag; a wire bending portion; and an extending portion which is arranged at the distal end portion of the sheath so as to protrude forward from the distal end portion along the longitudinal axis and enter an inside of the bag. The extending portion intersects with the opening surface that is defined by an opening end of the opening portion. The extending portion is configured to be capable of extending inside the bag from an opening surface toward the bottom portion.