A biopsy system includes an endoscope which includes an insertion section having a bending portion capable of being bent along a predetermined bending plane depending on the operation of an operation section and a treatment tool for endoscopes that has a needle tube, is inserted through the endoscope, and is capable of being fixed to the endoscope by a fixing unit in a state where the treatment tool is inserted into the endoscope. A portion of a distal end side of the needle tube is squeezed in a radial direction and thereby formed as a flat portion having a major axis and a minor axis. The treatment tool for endoscopes is fixed by the fixing unit so that the minor axis of the flat portion of the needle tube becomes parallel to the bending plane in the state where the treatment tool is inserted through the endoscope.
