PROBLEM TO BE SOLVED: To provide an operation tool making a disposable type cylindrical pipet usable in a user-friendly manner and with high accuracy.SOLUTION: An operation tool for operating a displaceable type cylindrical pipet at least includes: a cylinder body 2 a fastener 3 and a push rod 4. The cylinder body 2 includes: an insertion part 2a having an outside diameter that can be inserted into the cylindrical pipet 1 at least in the substantially front part thereof and a slim part 2b formed in a reverse-tapered state in which the outside diameter of the cylinder body is gradually decreased as it goes from the front to the rear, in a partial range of the outer periphery in a partial range in the major axis direction of the insertion part 2a. The fastener 3 is substantially cylindrical and has such an inside diameter as to be freely slidable at least in a partial range when being fitted to the insertion part 2a, and is capable of fixedly holding the displaceable type cylindrical pipet by being slid to be fitted to the slim part 2b. The push rod 4 penetrates through the cylinder body 2, is capable of being slid on the interior of a cylindrical part 1c, and can operate a content of the pipet 1 so as to freely discharge and suction the content.
