The poor conditions of storage in the basement of the Egyptian Museum were the reason for severe damage to an unknown multi-piece mummy cartonnage dating back to the Late Period (780 BC-332 BC). This mummy consists of five separated pieces (a mask, a pectoral, an apron, a stomach, and a foot) on canvas support topped by a ground layer decorated with green, yellow, red, black, and white colors and a gilded layer. All the pieces of the mummy cartonnage have damage in the form of separations, cracks, discoloration, tears, and brittleness in the layers of the canvas support. The research paper presents the result of an examination and analytical study for the layers' structure of the mummy cartonnage. Therefore, the Optical Microscope (LOM), visible light, Scanning Electronic Microscope (SEM), EDX, Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and XRF Spectroscopy were used. The results showed that canvas support made of linen in the form of four layers of thin fiber was used in the mask, stomach, and apron pieces. In contrast, one layer of thick fiber canvas was used in other pieces (mask, foot, and pectoral). The ground layer consisted of calcium carbonate, traces of gypsum, and quartz. The painted layer included Egyptian green, malachite, hematite, goethite, goethite with orpiment, graphite, and under layer of Egyptian blue below the green, red, and yellow pigments in a unique technique, especially in the pectoral and foot pieces. It was also noted that animal glue was used in all pigments and colors as a binding medium.