A door for a motor vehicle includes an outer panel and an inner panel in which window portions are formed at their upper side region and which are connected at their peripheral portions, a space which is formed between the lower side region of the outer panel and the lower side region of the inner panel and in which a window glass for opening and closing the window portions is disposed so as to be able to move up and down, a module mounting opening formed on the lower side region of the inner panel and a module structure constituted by mounting a plural functional components to a module base, wherein the module base is fluid-tightly fixed to the module mounting opening at its peripheral portion and the module structure is mounted on the inner panel.