PURPOSE: To improve accuracy in working the inside and outside spherical surfaces by revolving around its own axis or revolving about a mastershaft a cutting device body in which a tool rest capable of feeding at a right angle to a spindle is mounted on an end of the spindle capable of rotating at right angle to the master shaft and moving axially.

CONSTITUTION: The inside spherical surface is generated by securing fixedly a main body 4 to a column 1 with bolts 8, setting the spherical center of a surface 25 to be cut to the intersection point of the respective center lines of a transmission shaft 15 and a spindle 19, moving a cutting tool 21 on a tool rest 20 or moving the spindle 19 axially to locate the cutting tool, driving a motor 16 to rotate the spindle 19 through the shaft 15 and bevel gears 17, 18, further driving the motor 12 to rotate a tubular shaft 11 for revolving the cutting tool along the surface 25 and feeding the cutting tool on the tool rest toward the center while moving the spindle 19 radially. The outside spherical surface is generated by removing the bolts 8, enabling the main body 4 to be rotated about the axis 3 and giving circular movement to the cutting tool while driving a motor 10 to rotate the main body 4 and revolve the cutting tool.