In this paper, uniaxial force sensor unit with single amplifier is developed. Four strain gauges attached to thin elastic plate constitute a bridge circuit which counts normal component of acting force automatically. It is easy to implant a uniaxial moment sensor in the unit independently. As an application of developed sensor unit, a whisker sensor system, which is simply composed of a flexible tactile beam and two force/moment sensor units, is proposed. The system is able to detect contact location between the flexible beam and an object. Contact force when the beam makes contact at its tip end is experimentally examined.