PURPOSE: To make a handy version of square chisel machine and simplify cutting work portion by appropriately providing thread portion on the drill itself and constructing so as to generate push-pressure (cutting force) of square chisel case in drilling by the drill and the material to be cut.

CONSTITUTION: Thread portion 17 with diameter (c) of thread ridge larger by a minute dimension (d) than drill tip boring diameter (a) and outer dimension (b) of square chisel case 1 has been provided at the tip circumference of drill 4 protruded outward from the tip of the square chisel case 1 so as to be possible to screwing into the material to be cut and monolithic to the drill 4. When the material to be cut is bored with the drill tip boring portion 16, the drill 4 advances while the thread portion 17 is screwing into the material to be cut along that hole. This advancing force exerts push-pressure to the square chisel case 1 through gear shaft 8, bearings 6 and 7, gear case 5 and the like. Accordingly, is possible to device automated cutting.