Silver(I)-selective CHEMFET devices based on plasticized membranes have been developed. It has recently been shown by the authors that simple molecules containing a thioether group are good Ag+ sensing molecules. In this work the monothioether diphenyl sulfide PhSPh molecule has been used as the sensing ionophore for silver CHEMFETs. The devices have shown a Nernstian response, good selectivity coefficients for interfering ions and linear responses over three decades of silver activity. © 1995.