An electrical connector (100), comprising an insulative housing (1) defining a base portion (11) and a mating portion (12) extending from the front side of the base portion along a mating direction; a plurality of passageways (114) disposed in the base portion with an opening backwards and extending along the mating direction; a plurality of receiving spaces (121) disposed in the mating portion and communicating with the complementary passageways; a plurality of contacts (2) mounting to the insulative housing along the mating direction, and each contact including a flat base part (21) mounting to the base portion of the insulative housing, a connecting part (22) extending forwards from the base portion and received in the passageways, a mating part (23) extending from the connecting part and disposed in said receiving space, and a spacer part (24) located between the base part and the connecting part; wherein the spacer part covers the opening of the passageways.