A microrobot that can be moved along blood vessels has a great potential application for microsurgery. This paper discusses the development of a wireless microrobot that can be manipulated inside a tube using an external magnetic field. The model microrobot utilizes an electromagnetic actuator as the servo actuator to realize movement in biomedical applications. The structure, motion mechanism, and characteristic evaluation of a driving fin used for propulsion have been discussed. The fishlike fin movement can be controlled via frequency adjustments to the alternate magnetic field. Vertical movement of the microrobot can be stopped at a specified location. Experimental results indicate that the microrobot can be controlled upward, downward, and also be suspended in water using frequency adjustments. The microrobot has a rapid response, and can correspond to the dirt adhering to the inner wall. This device will play an important role in both industrial and medical applications such as microsurgery.