A pair of electrical connectors for releasably connecting a first terminal with a second terminal, comprises: a first connector having a first terminal; a second connector having the second terminal; a manual lever having a base end so mounted on the first connector as to be rotatable in a plane parallel to an insertion direction of the first connector into the second connector, and a free end; an engaging arm provided with a base end rotatably mounted on an intermediate portion of the lever and a free end formed into an engaging portion; engaging means including a hook for catching the engaging portion of the arm, an abutting portion on which the engaging portion of the arm abuts, the hook and abutting portion being provided in the second connector as to be releasably engaged with the engaging portion of the arm. In a preferred embodiment, the connectors further include a spring member for biasing these connectors during connection so as to be separated from each other in the insertion direction described above.