The Dark energy Camera (DECam) requires a Shutter with a clear aperture of 600 mm. This is larger than any astronomical Shutter that has been built to date. At the same time, the accuracy and reproducibility of the Shutter Mechanism employed is crucial to the success of the Project. To minimize vibrations, the Shutter shall be impact-free. This can be achieved by a slit-type Shutter with low acceleration light weight blades driven by computer controlled stepper motors. In order to achieve the required photometric precision absolute timing accuracy of better than 10 ms has to be guaranteed at any point across the aperture. Requirements on Shutter exposure time accuracy and repeatability are 50 ms and 5 ms, respectively. The Dark Energy Camera will be installed on the Blanco 4 m telescope at CTIO in Chile and thus all components have to be able to withstand the harsh mountain environment. The Shutter performance has to be maintained from -5 Degrees C to +20 Degrees C and from 0 to 100% relative humidity.