An electrical connector and a method for fastening the connector to a circuit board has a connecting chamber in which a conductor rail is arranged. The conductor rail is electrically connected at a connecting side of the electrical connector to an electrical connecting part make electrical contact at a contact side with a circuit board. The conductor rail includes a connecting arm for connection with the electrical connecting part and a contact arm for connection with the circuit board. The connecting arm and the contact arm are joined together by a connection arm. The connecting part is displaced in a connecting direction extending parallel to the conductor rail for connection with the conductor rail. The contact arm is designed as a spring in order to press against the circuit board when they are connected. The conductor rail can be positioned in two mutually rotated positions and the electrical connector may have at least two adjacent connecting chambers.