An instrument (10) for gravimetrically determining moisture content has a housing (20), with a weighing device (40) arranged inside. The weighing device (40) has a load receiver (60) onto which a sample (62) is placed. The housing has a stationary housing part (21) and a movable housing part (22), the movable housing part alternately occupying a measuring position and a loading position. In the loading position, the respective housing parts are spaced apart from each other, allowing a sample to be put on the load receiver. In the measuring position, the respective housing parts form an essentially enclosed testing compartment (30) that surrounds the load receiver. A means (70), arranged in the testing compartment, heats a sample that is placed on the load receiver. The movable housing part is moved between the respective positions by a position-changing device.