PURPOSE: To restrict the abrasion of a nozzle hole as little as possible with a grain deposition layer, which is formed automatically, to improve the durability by forming multiple stages of shelves, which project toward the axis side of the nozzle hole, in the inner peripheral surface of the nozzle hole of an abrasive nozzle with a predetermined space in the axial direction.

CONSTITUTION: In an abrasive nozzle 4, multiple disc spring shape shelves 10 are formed on the inner peripheral surface of a nozzle hole 42 with a predetermined space in the axial direction thereof, and the direction of each shelf 10, 10,... is directed to upstream of the jetting direction so as to be located downstream of an orifice. As a result, in the case where a high pressure water jetting nozzle is used to generate a jet and where this jet is contaminated with abrasive grains A, A,... to be used for the cutting work, the abrasive grains A, A,... close to the periphery of the jet collide with the shelves 10, 10,... as the use time elapses because of the shelves 10, 10,... and are piled gradually, and finally, the abrasive grains A, A,... are filled in respective annular spaces 11, 11,... formed between two shelves 10, 10 adjacent to each other, and grain sedimentary layers 12, 12,... are formed.