A new irrigation sucker (Delta Irrigation Sucker ) was designed for microneurosurgery. The Delta Irrigation Sucker has a unique trigonal pyramid-shape thumb piece, providing a very stable grip. Irrigation is achieved easily by pushing a small button just behind the pressure-regulating pore. Stable hold of the sucker and easy handling of the irrigation button enable irrigation without unsteadiness of the sucker. The Delta Irrigation Sucker is available in six sizes, with diameters from 1.5 mm to 4.0 mm at 0.5 mm intervals. Irrigation force is provided by a pressure bag, and a normal sterile transfusion set can be used as the irrigation circuit. The Delta Irrigation Sucker was used in 20 cases of clipping for ruptured cerebral aneurysm, five cases of tumor resection, and three cases of anterior clinoidectomy and opening of the internal auditory meatus. Subarachnoid clot was easily removed and the bleeding points were easily confirmed. Irrigation, controlled by natural finger movement, did not cause unsteadiness of the sucker.