An attitude control algorithm of a free-flying space robot with thrusters is proposed. It is known that the motion of the manipulator attached to the main body of a space robot causes the attitude deviation of the main body because of dynamic interaction, and an effective attitude control algorithm is desired. An equation of motion for the attitude of the space robot is derived using the Lagrange equation. The proposed disturbed-torque compensation algorithm, which is a kind of feedfoward control, is as follows. The inertia force, which is calculated from the equation of motion, is considered as the disturbance torque for the main body. Thrusters act to compensate the impulse of the disturbance torque. The proposed algorithm is compared with the time optimal control and time-fuel optimal control algorithms. Simulation results of attitude deviations and input energy are discussed.