An electrical connector includes a plurality of pin contacts, at least two inserts each having inserting holes for inserting and arranging the pin contacts therein, holders for holding the pin contacts relatively to the inserts, a shell forming a fitting opening and having a fitting device to be fitted with a mating connector, a fixing device for fixing the inserts to said shell, and a sealing member for preventing moisture from a casing. One insert located on the fitting opening side is formed from a sealing member, and outer circumferences of the inserting holes on the sides of the inserts in contact with each other are in fitted relationship of projections and recesses. A space is formed between the shell and an outer circumference of the insert nearest to the connection side, and a pouring opening is provided for pouring a waterproof material so as to reach the surface of the insert in contact with the insert nearest to the connection side. A waterproof material is caused to flow through the pouring opening into the space and between the respective inserts so as not to reach the pin contacts to improve waterproof property on the connection side, thereby preventing defective connection due to dew condensation.