Abstract: A potentiometric probe, comprising: a housing, which has a first chamber, in which a reference half-cell is formed, which is in communication with a medium surrounding the housing via an electrolytic contact location arranged in a wall of the housing. The housing has a second chamber, in which a measuring half cell is formed, wherein the second chamber is closed on one end by a measuring membrane, such that a surface area of the measuring membrane facing away from the second chamber is in contact with the medium surrounding the housing, and wherein the measuring half cell has a lengthwise extension between the measuring membrane and a closure element bounding the measuring half cell on an end lying opposite the measuring membrane. A quotient of a separation of the measuring membrane from the closure element and an outer diameter of the housing amounts to less than 5, especially less than 2.