An electrical connector is provided and includes a housing having a pair of side walls defining a plurality of terminal grooves therein and a bottom wall connecting with said side walls and defining a top face facing upward. A plurality of terminals are received in said terminal grooves, each comprising a retaining portion and a contacting portion extending from the retaining portion, said contacting portion having a connecting portion cantilevered above said top face. The bottom wall defines a plurality of through holes running therethrough along a vertical direction and facing to an end of the connecting portion which is far away from the retaining portion, and said top face of the bottom wall extends slantwise from the through hole to the side walls therefore places adjacent to the through hole are lower than those adjacent to the side walls in said vertical direction.