Electrical connector

An electrical connector comprising:

• a first connector part having a first housing and a first contact supported by the first housing, the first connector part being mounted on a first substrate;
• and
• a second connector part having a second housing that is capable of accommodating the first housing and a second contact supported by the second housing, the second connector part being mounted on a second substrate;
• wherein
• the first contact and the second contact are contacted with each other by coupling the first connector part and the second connector part so as to accommodate the first housing in the second housing,
• the first connector part and the second connector part are provided with a first assistant fitting and a second assistant fitting, respectively, to ensure coupling strength of the first connector part and the second connector part,
• the second assistant fitting of the second connector part includes a cantilevered lock beam having a deflection part extending in a direction substantially parallel to a connector mounting surface of the second substrate and in the outside of the second housing, and
• the first assistant fitting of the first connector part includes an engagement part that pushes aside the free end of the lock beam and rides over the free end of the lock beam so as to be engaged with the free end of the lock beam when the first connector part is coupled to the second connector part.