A puncture needle includes a needle tube 1 provided with a spiral groove 3 and wall surfaces 3a and 3b of the spiral groove 3 serve as a surface for reflecting ultrasonic waves. The spiral groove is formed on the peripheral surface of the needle tube such that a grinding stone 2 is brought into contact with the peripheral surface of the needle tube while the needle tube 1 is being moved in its axial direction and rotated.The wall surfaces of the spiral groove formed on the needle tube serve as a reflection surface to change the orientation of the reflection surface in the axial direction of the needle tube according to change in position of the spiral. Therefore, even if a direction in which an ultrasonic wave is applied to the puncture needle is fixed, any portion of the reflection surface changing in orientation can become a surface for reflecting well ultrasonic waves, so that good ultrasonic waves can be obtained. The slant angles of the reflection surfaces in the axial direction of the needle tube can be changed by adjusting the moving speed in the axial direction of the needle tube or the rotation speed.
