Moisture content and water activity are important parameters for quality characterization of products like bulk materials, powders, granules. Thus, an exact determination is necessarily required in a wide range of industrial applications. Moisture of materials is the content of non‐chemically bound water in a solid or liquid. Water activity (aW) is a characteristic/parameter of the non‐chemically bound (ʺfreeʺ) water in materials and is measured as humidity over a solid/liquid surface at constant temperature (equilibrium moisture content). It is an important parameter to characterize the quality of e. g. pharmaceutical and food products. In our contribution, we present the developed MOISHUM device for staged determination of water activity and moisture content of liquid and solid materials