This paper discusses a design of micro-structure on the surface in contact with human from the standpoint of frictional property and feeling. Coefficient of friction on a floor varies with sliding speed in wet environment. At some condition where hydrodynamic pressure becomes dominant, the coefficient decreases and causes slip. Experiments were carried out on a special setup and structural design to decrease this pressure was discussed. It was found that structures of sub-millimeter pitch are effective in floor design. Then, the surface structure for handles was discussed. In this case, feeling becomes important rather than the change in sliding speed condition. It was found that sub-millimeter sized structure can improve the feeling while keeping high coefficient of friction under wet condition.