Abstract: A drilling machine includes a base located on a horizontal surface, a post provided on the base, a worktable movably connected to the post and a drilling unit provided on the post. The drilling unit includes a direct-current brushless motor, a drill and a transmission. The direct-current brushless motor is provided on the post. The drill is operatively connected to the direct-current brushless motor. The transmission includes a circuit board and gear-related buttons operable to instruct the circuit board to convert an alternating current into various direct currents to cause the motor and, therefore, the drill to rotate at various rotational rates.