A sensor (30) for measuring a biological potential of an individual, comprising: - a measurement electrode (31) comprising a base (32), at least one leg intended to come into contact with an anatomical zone of the individual and at least one electrical connection member (38), - at least one locking member (45) configured to cooperate in a reversible manner with at least one complementary locking member (25) on an external support (10) so as to removably fasten the sensor (30) to the external support (10), the locking member (45) being separate from the electrical connection member (38), - a protection element (40) made from a resilient material and delimiting a recess (41) in which the leg extends.
