A conductive conductivity sensor, comprising: a probe immersible in a measured medium. The probe has an inner space, which is connected to an environment of the probe via at least one opening leading out from the inner space and in which are arranged two electrodes, which are supplied with an alternating voltage during measurement operation and which have inner surfaces facing into the inner space and outwardly facing outer surfaces covered by insulation, wherein the inner surfaces have edge surfaces adjoining the openings. Measuring characteristics of the conductivity sensor have a smallest possible dependence on objects arranged in the vicinity of the conductivity sensor. At least the edge surfaces adjoining one of the openings have a surface geometry directing thereon beginning or ending, electric field lines in a direction facing away from such opening and into the inner space.