PURPOSE: To realize improvements in durability and reliability of a flat cable, by a method wherein at the time of holding of the flat cable, stress which has been concentrated so far is reduced or dispersed by making use of a reinforcing plate.

CONSTITUTION: At the time of holding of a flat cable, the same possesses such a reinforcing plate 8 that a deformation of the flat cable under a bent state into two sides on the same position, which is generated by reciprocation of a movable part, is allowed to approach deformations under bent state to one side on at least two positions. Then the title constitution is such that the reinforcing plate 8 possesses elasticity of certain extent and lower flexibility than that of the flat cable.