This paper deals with designing a device for food processing industry, i.e. a multifunctional sterilizer (MFS) to be used for extending the shelf life of food, such as meat, fish, fruit and vegetables, packaged in containers of various capacities made of popular materials such as glass, tin and thin film. Having analyzed the existing solutions regarding the choice of the heating medium used in sterilization systems, the authors showed that when selecting a new sterilizing device many criteria need to be accounted for, some of them being rather contradictory. Thus the authors suggest to apply a multiple criteria decision making approach which is used in other areas of research. For that purpose, a coherent group of criteria for different types of heating medium was suggested. Based on the decision maker’s preference model, a final ranking list was prepared using the method based on the prevalence relationship - Electre III. The obtained results were subsequently summed up.