This paper presents a technique for characterizing the complex permittivity of non-solid materials. A container, whose materials have been previously characterized, is used. The container and the method make it possible to test liquids, powders and their mixtures separately. The characterization method is the same as used for a solid material. Experimental validation was carried out in the W band (75-110 GHz) on different types of materials such as sand, sugar and water. The comparison between the measured and simulated S-parameters for each material shows very good agreement.