Display cabinet is the most widely used equipment to keep food at the required temperature in supermarket. Despite a good design and good control of operating conditions in stores, the heterogeneity of the temperature inside the display cabinet has been observed in several studies. This temperature difference is mainly due to thermal losses through walls, the infiltration of outside air and the heterogeneity of the evaporator temperature. The aim of this work is to develop a transient heat transfer model to study the temperature evolution of loaded products and air inside a display cabinet. The developed model is validated by experimental data obtained with different operating conditions. This model is combined with a model describing the melting and freezing process of a PCM unit located inside the display cabinet. The global model can be used to study the effects of PCM addition on air and food temperatures.