In order to understand the state of the glue in wood-based panels and the effect of their Microstructure on their basic characteristics, microstructure of wood-based panels has been studied by SEM and Stereo Optic Microscopy. This paper compares the main differences between the result obtained from optic and electron microscopies, explains the basic requirements of the specimen, and discusses about the photographs taken under the SEM. Studies reveal that different cut surfaces of wood grain give different surface qualities; Veneer quality of the plywood influences the thickness of the glue; the fiber brooming of fiberboard is some what different from that of paper; shear failure of plywood occurs usually both in the wood and in the interface between the glue and the wood.