This paper is intended to report an effectiveness of micro-structuring for anti-slip surface. The experimental set-up developed in the present work enables us to measure friction force between elastic body sample on a substrate surface under dry and wet conditions. The substrates of unsaturated polyester were grooved with pitch ranging from 12 μm to 1500 μm. The maximum value of friction coefficient is obtained on 300 μm pitch of grooves in the tested conditions. The Stribeck curves show that appropriate pitch of grooves allows the specific value of ηV/p minimizing friction coefficient to become larger. This result indicates that the micro-structures limit the decrease in friction coefficient with sliding speed. Some sensory tests show sub-millimeter scale of structure does not change undesirably tactile impression, while it maintains high friction coefficient under wet condition.