Disclosed is a pH sensor comprising a carrier (10) comprising a plurality of conductive tracks and an exposed conductive area (40) defining a reference electrode connected to one of said conductive tracks; a sensing device (30) mounted on the carrier and connected at least one other of said conductive tracks; an encapsulation (20) covering the carrier, said encapsulation comprising a first cavity (22) exposing a surface (32) of the sensing device and a second cavity (24) exposing the exposed conductive area, said second cavity comprising a reference electrode material (42) and an ion reservoir material (44) sharing at least one ion type with said reference electrode material, the reference electrode material being sandwiched between the exposed conductive area and the ion reservoir material. A method of manufacturing such a pH sensor is also disclosed.