A demountable display module that is stored in the form of a briefcase is described; it comprises a base formed by panels; a cover demountably attached to the base; posts that are demountably to the frames of the side panels of the base; and a board demountably attached to the upper end of the posts. Within the base, there is a first shelf and a second shelf each of them is housed in the inner part of one of the side panels. Likewise, first and second support and securing means are provided to keep the shelves in horizontal position and to secure the shelves in vertical position when they are housed in the side panel to which they attach. The cover of the module is used as a container body to house the rest of the elements of the module and it includes a handle to transport the module in the form of a briefcase; likewise, the method to manufacture the module is described.