To provide an excavating machine capable of making the bottom surface of a formed hole flat.

The excavating machine 1 for forming the hole by downwardly excavating a surface to be excavated includes a drill bit 20 which is supported by a drill body 11 from above. The drill bit 20 includes an internal tube 30 and an external tube 40. The internal tube 30 is cylindrically-shaped in its upper section, and is tapered down to its lower end in its lower section. The external tube 40 has a horizontal lower end surface. The excavating machine 1 excavates the hole so that the bottom part of the hole becomes cone-shaped by using excavating blades 37 for drilling provided on the lower end surface of the internal tube 30 when the lower end surface of the external tube 40 is positioned above at least one portion of the lower end of the internal tube 30. On the other hand, the excavating machine 1 excavates the hole so that the bottom part of the hole becomes flat by using excavating blades 43 for forming a flat surface provided on the lower end of the external tube 40 when the lower end surface of the external tube 40 is positioned below the whole surface of the lower end surface of the internal tube 30.