PURPOSE: To make it possible to carry out excavating and unloading work at a high speed without generating a large impact vibration.

CONSTITUTION: This device comprises a drive shaft 34, which is covered with a cutter case 33 and which is pushed in under-ground while it is being driven rotatively. An excavation blade 35 is mounted to the tip of the drive shaft 34 while a rotor 37 is mounted to the drive shaft 34 in the rear of the excavation blade 35, thereby excavating the earth with the excavation blade 35 by the rotary motion of the drive shaft 34. At the same time, an earth and sand chamber 41 is installed outside the cutter case 33 so as to place the excavated earth and sand carried with the rotor. This device also comprises an earth removal pump 49 which brings out the excavated earth and sand kept in the earth and sand chamber 41 to the ground. The ground is excavated with the excavation blade 35 by the rotary motion of the drive shaft 34 while the excavate earth and sand is carried in the cutter case 33 with the drive shaft 37 and discharged into the earth and sand chamber 41. The excavated earth and sand, earth ana sand, which is discharged into the earth and sand chamber 41, is brought out to the ground by means of the earth removal pump 49. This construction makes it possible to excavate the ground and unload the excavated earth and sand continuously at a high speed without generation a large impact vibration.