A robot control apparatus capable of effecting the lead-through teaching easily and safely. When an operator presses down a lead-through teaching effective switch (12) provided in a control apparatus body, the supplying of electric power to a servo controller (17) is stopped, and a mechanical brake (18) is made effective. When the operator presses down a dead-man switch (4) with a teaching handle (3) gripped, an electromagnetic relay (RL1) is energized and a normally opened contact (14) is closed. Consequently, the mechanical brake (18) is made ineffective, and an electromagnetic relay (RL2) is energized at the same time, so that a normally opened contact (15) is closed to cause a power source current to be supplied to the servo controller (17). A signal making a torque instruction zero is also sent to the servo controller (17). This enables the operator to move a robot in a desired direction. When the operator discontinues to press down the dead-man switch, the mechanical brake is made effective immediately, and the robot is locked in the current position.