To develop further a plug connector and its attaching method maintaining a certain electric connection of two contact points, and reducing its manufacturing cost at the same time.

A 1st insulated body 10, connection contact points arranged in the 1st insulated body 10 and prepared for connecting to conductors, a 2nd insulated body, and at least one insertion contact 26 arranged in the 2nd insulated body for connecting to an auxiliary plug connector, are prepared. The insertion contact and the connection contact are connected mutually in an electric- conduction form, by insertion connections 18 and 32. The insertion connections are formed with two elastic tabs 32 and 32' prepared on one of the contacts, and collaborating with the other contact.