An electrical connector comprising a housing made of insulator, conductive contacts arranged in the housing and an actuator attached rotatably to the housing, wherein the conductive contacts are divided into at least first and second groups, and the actuator brings each of the conductive contacts belonging to the first group into press-contact with one of connecting terminals on a circuit board partially inserted into the housing in a first predetermined manner and each of the conductive contacts belonging to the second group into press-contact with another of the connecting terminals in a second predetermined manner different from the first predetermined manner so that a time difference is brought about between a first time point at which the conductive contacts belonging to the first group exert the maximum retroactive force to the actuator and a second time point at which the conductive contacts belonging to the second group exert the maximum retroactive force to the actuator.