An endoscope auxiliary tool includes a first support section which is formed to extend along a longitudinal axis, a second support section which is formed substantially in parallel to the longitudinal axis of the first support section, a first protrusion section and a second protrusion section which are formed at distal end sections of the first support section and the second support section, respectively, and disposed more distal than the distal end section of the endoscope to sandwich an axis of a channel having an opening at the distal end section of the endoscope, and a positioning section which is configured to position the first protrusion section and the second protrusion section with respect to the distal end section of the endoscope such that the first support section and the second support section are inclined to the axis of the channel.
