A piezoelectric/electrostrictive membrane sensor is provided, wherein a piezoelectric/electrostrictive body contains an alkali metal or an alkaline earth metal, and a sulfide and the main component of terminal electrodes are contained near the surface of the piezoelectric/electrostrictive body. A voltage equal to or higher than a withstand voltage is hardly applied to the piezoelectric/electrostrictive body, and consequently, the sensor is prevented from dielectric breakdown. In addition, the sensor is hardly electrostatically charged, and thus prevented from electrostatic discharge damage and attraction of dust, dirt or the like.