PURPOSE: To prevent earth from falling when pulling up the main body of an earth auger by installing a helical band on the outer periphery of a helical blade fixed to a hollow shaft, and also attaching to the end of the main body a head provided with a helical band and an elastic plate similar to those of the main body, and having a bottom plate.

CONSTITUTION: An earth auger main body 4 is comprised of a screw blade 2 fixed around a hollow shaft 1 and a helical band 3 installed on the outer periphery of the blade. An auger head 9 provided with a screw blade 6 and a helical band 30 both similar to those of the main body 4, a drilling bit 31, a bottom plate 35 and an elastic plate 40 serving as a nonreturn valve is attached to the end of the main body 4. Earth is prevented from collapsing during drilling and is also prevented from falling when the auger is pulled up. Thus, earth remaining in the drilled hole is surely removed.