PROBLEM TO BE SOLVED: To provide an electric connector having a female member and a male member configured so as to prevent the female member from being coupled electrically with the male member, when the electric coupling inverts the polarity of the electric connector.SOLUTION: A female member may have first and second chambers. A male member may have first and second extensions. The first and second chambers may be configured so that the first and second extensions can be inserted and housed therein. The female member may have one or more elastic members providing a pressing force for biasing at least a part of the male electrode for at least a part of the corresponding female electrode. Alternatively, the cover of the male electrode in the first and second extensions may have an elastic member.