PURPOSE: To perform excavation over a wide range, by a method wherein plural injection nozzles for carrying excavated soil by a flow are located to the inner peripheral wall of a connection between a suction pipe and a delivery pipe and nozzles for excavation are installed to the outer peripheral wall of the suction pipe to form an excavator, and the excavator is elevatably suspended from a ship.

CONSTITUTION: Plural injection nozzles 3 for suction are aligned along the peripheral direction of the inner peripheral wall of a connection between a suction pipe 1 and a delivery pipe 2, injection is effected in a direction of suction, and plural injection nozzles 4 for excavation are arranged along the peripheral direction of the outer peripheral wall of the suction pipe 1 to form an excavator. Water is fed to the nozzles 4 through an introduction passage 14 and driving fluid and the air to the nozzles 3 through a delivery pipe 12 and an air pipe 13. Further, an excavator A is elevatably hung down from a crane on an excavating ship D, a flexible pipe 6 is connected to the delivery pipe 2 of the excavator A, and excavated soil is carried by a flow. This enables to perform excavation over a wide range.