To provide a small jack that has an improved fabrication and durability, etc., by making an improvement of a contact and that, in particular, has sufficient holding force to prevent unplugging.

The jack is equipped with a switch which comprises fixed contacts 4, 5 and movable contacts 6, 7 that are contacted and separated from each other by insertion of a plug, (normally not in contact or separated from each other) and the fixed contacts 4, 5 and movable contacts 6, 7 are respectively composed of wire material. The jack is also provided with a holding part 11 composed of wire material, which holds the plug inserted to the jack body 2.