Abstract: A locking device for a connector includes latch springs and latch supports for pivotally supporting the latch springs on a plate of connector. The latch support has an end face consisting of a series of a flat face perpendicular to a rotating axis of each of bent ends of the latch spring, a width differential face continuous to the flat face and obliquely protruding in an axial direction of the bent end of the latch spring away from the flat face, and a gently inclined face continuous to the width differential face on opposite side of the flat face and obliquely depressing in an axial direction of the bent end of the latch spring away from the width differential face. Base portions of the latch spring are in contact with the flat faces, in contact with the width differential faces and in contact with the gently inclined faces, when the latch spring is in a vertical, a predetermined inclined and a horizontal position, respectively.