An endoscope cleaning/disinfecting apparatus connection tool includes: a first fluid passage portion and a second fluid passage portion each including an end that is in communication with a fluid supply apparatus connection portion; an endoscope connection portion including a first discharge portion and a second discharge portion to be connected to an opening portion that is in communication with a conduit included in the endoscope, the first discharge portion and the second discharge portion being provided at respective other ends of the first fluid passage portion and the second fluid passage portion, the first discharge portion being inserted into the opening portion and discharging the fluid passed through the first fluid passage portion to an inside of the conduit, the second discharge portion being arranged at a circumference of the opening portion and discharging the fluid passed through the second fluid passage portion to the circumference of the opening portion.