A muscular strength enhancing robot to be driven by an intention of a user and a method of driving the robot are disclosed. The robot includes an actuator attached to a portion of a body of the user and configured to be actuated by enhancing a muscular strength, an encoder connected to the actuator and configured to measure an actual velocity at which the actuator moves, a force or torque sensor configured to measure an intensity of a force to be applied, an admittance modeling module configured to calculate a target velocity using the intensity of the force, and a proportional integral derivative (PID) control module configured to control actuation of the actuator in proportion to a velocity difference between the target velocity and the actual velocity, control the actuation by a cumulative value of the velocity difference, and control the actuation by a difference between a previous and a current velocity difference.