To solve the problem that conventional back jet-type suction conveyance equipment for use in the excavation and removal of accumulated mud disables continuous suction conveyance due to the application of local suction to only the periphery of a suction port when the target mud and the like have no fluidity, and makes working efficiency low because the suction port is apt to be clogged with solid matter.

An agitating blade is set in a bucket 11 which is expanded from the suction port 21; and a suction conveyance mechanism and an excavation and agitation mechanism are integrated together to enable the continuous suction of the mud with no fluidity. The excavation is performed concurrently with the rotation of the agitating blade; and excavated sediment is sucked in while being crushed by the agitating blade, so as to enable the continuous suction of the mud with no fluidity.