PURPOSE: To facilitate the fixing of a probe and a member for sampling an organism tissue even when a paracentesis needle is set being tilted to an axial direction of an ultrasonic probe by forming a fitting groove which allows the fixing of the organism tissue sampling member on a grip part of the ultrasonic probe.

CONSTITUTION: A grip part 14 is a part which an operator holds when using an ultrasonic probe 10 and a fitting groove 16 is formed to allow the fixing of a sampling member 5 thereon. The fitting groove 16 is so formed that a body 1 of the sampling member 5 is fitting into the grip part 14 of the ultrasonic probe 10 when a paracentesis needle 2 is put through into a needling hole 12. With such an arrangement, the ultrasonic probe 10 can be grasped together with the sampling member 5. Therefore, even when the needle 2 is tilted to an axis of the probe, the ultrasonic probe 10 and the sampling member 5 can be fixed easily with one hand thereby improving operability remarkably. This achieves a better stability of the sampling member 5 thereby enabling the sampling of a tissue piece of a desired part accurately.