PURPOSE: To eliminate the necessity for sharpening a worn tool, in a hole drilling device whereby the tool is revolved while turning on its axis, by optionally changing an angle of a turning spindle on its own axis with respect to a revolving axis and freely correcting the angle of a cutting tool edge.

CONSTITUTION: An angle of a cutting tool 7 with respect to a rotary shaft of a revolving main spindle 3 in a machining head can be adjusted by controlling adjusting screws 11, 12 to a desired angle used with a swivel pin 10 as the center. In case of wearing of the tool on the way of hole machining work, wearing of the tool can be recovered by adjusting an angle of the tool edge. A turning radius of the tool 7 can be changed even while the revolving main spindle 3 and rotating main spindle 6 are in rotation.