(EN) An ergonomically superior endoscopic suction-irrigation instrument for surgery comprises a telescope sheath (12) connected at an adjustable angle, preferably approximately 30°, to a vertically elongated handle (16) having thumb-operated irrigation and suction valves (62. 64) and a hook (86) for supporting the handle from the surgeon"s hand when the surgeon"s grip on the handle is loosened. The instrument is especially suited for sinus surgery.