A torque control device controlling torque of first and second mechanical units connected coaxially to each other through connecting members includes a controller generating first and second references from a command from a host system, first and second motors respectively driving the first and second mechanical units, first and second motor control units respectively controlling the first and second motors on the basis of the first and second references. The first and second references synchronously accelerate the first and second motors to first rotational speed, then increase rotational speed of the second motor according to a speed profile to produce torsional torque in the connecting members, decelerate the second motor to the first rotational speed after the torsional torque reaches a predetermined value, and synchronously decelerate and stop the first and second motors after a predetermined time period elapses.