To overcome such faults that it is troublesome to manufacture an excavating bit having two rotating bits or more provided in a circular front thereof, particularly, an excavating bit for excavating a hole with a small diameter (e.g. approximately 150 mm), because the area (commensurate with the diameter of a hole to be excavated) of the circular front of the excavating bit is limited, and such that the excavating bit thus manufactured lacks excavating performance and impact durability strength in excavation, particularly, due to reduction in size.

This excavating bit 1 of the excavating device for ground allows the excavation of the ground and the burial of a steel pipe. The excavating bit 1 is closely fitted into a recess 8 with an approximately rectangular front, which is formed in a central part of the circular front; and a planar backside 9 of the rotating bit 1a with an approximately rectangular front and left and right side surfaces 10 and 11 thereof are closely fitted into a planar backside of the recess 8 and left and right side surfaces thereof. An arc-shaped protrusive surface 12, in which a shaft hole drilled at a back end of the rotating bit 1a serves as a center, is closely fitted into an arc-shaped recessed surface 13 in which a shaft hole drilled at a back end of the recess 8 serves as a center; and a pivot 14 is fitted and inserted into both the shaft holes communicating with each other, so that the rotating bit 1a can be provided in such a manner as to be freely rotatable forward at a set angle, by making the pivot 14 serve as a center.