The present invention relates to a device for eliminating dust for a computer and a control method thereof. A control unit and a heat-radiating fan controlled by the control unit are provided in the main body. In addition, there is provided a cooling fin through which air stream formed by the heat-radiating fan passes. While the air stream formed by the heat-radiating fan passes through the cooling fan, heat is exchanged between the air stream and the cooling fin and the air stream is then exhausted to the outside of the main body. A vibration-generating element for generating vibration supplied with power is provided at one side of the cooling fin. The control unit controls the driving of the vibration-generating element. Vibration of the vibration-generating element is transmitted to the cooling fin to shake off dust accumulated on the cooling fin. Then, the air stream formed by the heat-radiating fan is exhausted to the outside of the main body together with the dust. Further, the driving of the vibration-generating element cooperates with the driving of the heat-radiating fan. According to the present invention so configured, the dust accumulated on the cooling fin is automatically eliminated by the vibration-generating element, whereby a cooling efficiency is enhanced and convenience in use is increased.