Microstructure of a paper-based packaging material was studied by acoustic microscopy method. The laminate structure of the packaging material contains paperboard, polymer and aluminium, which are widely used for aseptic liquid food package. The method has also been used to detect delaminations inside the material. The results show the possibility to study the micro structural features of paperboard, polymer and aluminium foil layered materials by applying the high-resolution ultrasonic acoustic microscopy. The potential for visualization defects in the body of this kind of materials is discussed in order to further develop the Non-Destructive Testing (NDT) method in food packaging industries.