A treatment instrument for an endoscope is provided that is suitable for cutting submucosa in endoscopic submucosal dissection. The treatment instrument for an endoscope includes a treatment portion having a cutting unit at a tip of an insertion portion that is to be inserted into the body. The main unit of the treatment portion is formed in a sawtooth shape having a peak portion and a valley portion. An electrode plate serving as the cutting unit is provided in the valley portion.
