Regarding the quality of structural concrete that is demolded during hydration, the porosity is not as dense as the surface layer because hydration is inhibited by drying. As a result, the strength of the surface layer is lower than that of the inside, and external deterioration factors easily enter, resulting in a decrease in deterioration resistance. In addition, since the surface concrete serves as the substrate for finishing materials, it is associated with problems such as adhesion and blistering of the finish. This chapter describes the inhomogeneity of moisture content and pore structure of concrete from the surface to the interior, strength distribution, resistance to deterioration, and peeling resistance of finishing materials.