Provided is a biological tissue collecting tool capable of reducing a variation in the amount of collected biological tissue at the time of collecting the biological tissue from a biological aperture. A biological tissue collecting tool 10 according to the present invention includes: an exterior body 3 having first space formed therein and having a first collection opening 2 formed in a wall thereof, the exterior body 3 having such a shape as to be insertable in a biological aperture a collecting portion 15 disposed in the first space such that the collecting portion 15 is movable in the first space, the collecting portion 15 being configured to collect a part of biological tissue that protrudes into the first space through the first collection opening 2 and an operating portion 7 connected to the collecting portion 15, the operating portion 7 allowing the collecting portion 15 to be operated from outside of the exterior body 3.
