A connector 10 which comprises a plurality of signal contacts 11, each of which is provided with two aligned first connecting parts 12a at one end and two aligned second connecting parts 12b at the other end and which form balanced transmission lines, further comprises a first holding member 13 which holds the first connecting parts 12a of the plurality of signal contacts 11 and a second holding member 14 which holds the second connecting parts 12b, intermediate parts of the plurality of signal contacts 11 between the first holding member 13 and the second holding member 14 being exposed to the air.