An electrical connector (100) includes a housing having a securing structure and a number of contacts (30). The securing structure defines a number of passageways (40) each extending therethrough along a thickness direction thereof, a number of securing recesses (42) each across and in communication with a corresponding passageway along a width direction thereof, and a number of air pockets (41) each across and in alignment with a corresponding passageway along a length direction thereof. Each contact has a body portion (32) inserted through the passageway, and a widen portion (31) secured in the securing recess and facing a corresponding air pocket.