The invention relates to a device (13) for constructing a laminar body (5) from a plurality of superimposed layers of free-flowing material, in particular particulate material, an a build platform (6) within a working area (11). The layers are solidified in locally predetermined regions by the action of binders and are joined together so that at least one molded body (4) is formed by the solidified and joined regions of the layers. The device comprises a discharging device (1) movable back and forth over the working area (11) in at least one discharge direction and having at least one discharge opening (14) from which the free-flowing material can be discharged in individual superimposed layers during the movement of the discharging device (1). According to the invention at least one body (8, 8a) defining the working area (11) in at least one discharge direction of the discharging device (1) and the build platform (6) are adjustable vertically relative to each other in accordance with the specific progress with which the laminar body (5) is being constructed, in such a manner that a surface of the at least one body (8, 8a) facing the discharge opening (14) is aligned flush with a laminar body (5) topmost layer that is yet to be produced or has already been produced, in order to dose the discharge opening (14) of the discharging device (1) and prevent the discharging device from discharging free-flowing material or in order to discharge free-flowing material not used for laminar construction into a collecting container (7) when the discharge opening (14) is located above the body (8, 8a).