<p>An endoscope treatment system has an endoscope having an insertion section, a channel provided along the insertion section, a treating unit insertable into the channel and having at its forward end a treating section, and drive means advanceable and retreatable in the direction parallel to the channel and passing the treating unit through the channel. An engagement member (advance blocking section or advance/retreat blocking section) for engaging the treating unit to a predetermined position at the forward end of the channel is provided near the forward end of the channel.</p>
