To provide an aspiration beak tube utilizing a compliant protective guard which minimizes risk for the damage to an organ and other body tissues.

This aspiration instrument which removes a material from a cavity of the body is equipped with a long and thin member 14 which regulates the longitudinal axis, and has a proximal end and a distal end. The long and thin member 14 has a longitudinal conduit which passes through the long and thin member 14 for making a fluid pass through. The aspiration instrument is also equipped with the protective guard 16. The protective guard 16 is arranged to be adjacent to the distal end of the long and thin member, regulates the longitudinal conduit and the opening section which is aligned axially, and allows the fluid pass from the cavity of the body to the longitudinal conduit. The protective guard includes a comparatively flexible compliant material to the distal end of the long and thin member, and is adapted for being substantially deformed in the engagement with the body tissue.