Abstract: A module cover is equipped with at least one door latch transmission mechanism for closing the entrance of a wafer transport module, each door latch transmission mechanism includes a door latch supported on a roller at the module cover, a latch bolt pivotally coupled between one end of the door latch and a part of the module cover, and a driving wheel coupled to the module cover and rotated to move the door latch forwards and backwards and to further turn the latch bolt in and out of a through hole on the module cover and a respective latch hole on the wafer transport module to lock/unlock the module cover.