A digital sign and a method of driving a digital sign are provided. The digital sign may include a case, a display panel provided in the case, and a circuit unit to drive the display panel. An inner space of the case may include a first space and a second space, with a first end of the first space connected to a first end of the second space. A suction port may be formed in the case to guide external air into the inner space, and a discharge port may be formed in the case to discharge the air from the case. A circulation fan may be provided in the inner space to induce flow of air in the inner space, and a circulation damper may be disposed between second ends of the first space and the second space to open and close the second ends thereof. The air introduced through the suction port passes through the inner space of the case and is discharged through the discharge port when the circulation damper is closed, and the air circulates in the first space and the second space when the circulation damper is opened.