A needle is formed in a three part structure composed of a small diameter tip part a middle part and a large diameter part wherein the small diameter tip part is fluid communicated with the middle part through a first taper part and the middle part is fluid communicated with the large diameter part through a second taper part the small diameter tip part is so formed that the inner diameter is set at 0.35 mm or more on the basis of the allowable deviation of a cumulus cell the outer diameter is set at 0.7 mm or less on the basis of the size of a small follicle and the inclination angle of an inclined tip and the length is set at 10 to 25 mm on the basis of the size of a dominant follicle the inner diameter of the middle part is set at 0.45 mm or more on the basis of the size of a cumulus cell the inner diameter of the first taper part is so set as to have an average grade of 10% or less in order to prevent the rapid deformation recovery of an oocyte cumulus cell complex during suction and the total length between the small diameter tip part and the middle part is so set that the large diameter part cannot penetrate through a tissue of a human body.
