Recently, waste incineration of wooden waste has been prohibited because of the dioxin problem and the recycle of them has been needed. Particle board (PB) and medium density fiberboard (MDF) are prospective recycle products made of wooden waste. This paper treats unsteady temperature and thermal stresses when we add the higher insulation with the grading inside property for such wooden recycle boards. The analytical model was assumed that the recycle board with higher insulation was used as interior wall. One-dimensional unsteady heat transfer problem was analyzed by the change of variable, the Laplace transform and the perturbation method. Various FGM higher insulation boards with same average density are discussed because the thermal conductivity of wood is proper to the density. The different direction of heat flow inside of board in summer and winter is also discussed.