We present simultaneous estimating the position and the mechanical impedance of unknown surfaces using a new robotic finger. Successfully treating such a simultaneous sensing device will contribute to reducing the inspection time required for industrial products, and could also be useful for detecting unknown surfaces such as in disaster zones. We propose a new robotic finger that is equipped with a force sensor and a resonant mechanical element on its fingertip. The force sensor is used as a surface detector to sense the reaction force from unknown surfaces, and the resonant mechanical part acts as a scaling amplifier to estimate the mechanical impedance of unknown surfaces. We verify the usefulness of our robotic finger by experiments. ©2006 IEEE.