The objective of this study is to align a certain axis of a spacecraft in an arbitrary direction by using a variable-speed single-gimbal CMG. Because the total angular momentum of the spacecraft is conserved in inertial space, the final attitude of the spacecraft is restricted, and it is possible to achieve pointing control of the axis that is orthogonal to the gimbal axis. Using new parameters to express pointing errors, we have proposed a simple pointing control law that can be used to align the pointing axis in an arbitrary direction in inertial space. The validity of the proposed control law is verified by numerical simulations.