PURPOSE: To secure further the connection of an electric cable to an electric apparatus by fastening an electric cable terminal to the terminal seat plate of the electric apparatus more tightly and stably when the electric cable terminal is to be connected to the electric apparatus.

CONSTITUTION: A protruded streak 3 for pushing an electric cable terminal 2 is provided between the screw hole and the side edge of the under surface of a washer 1, while a recessed notch streak 5 is provided on a part opposed to the protruded streak 3, on the upper surface of a terminal seat plate 4 on the side of an electric apparatus, and a fastening device of an electric cable terminal is thus provided. The protruded streak 3 is provided on the upper surface of the terminal seat plate 4, while the recessed notch streak 5 is provided on the under surface of the washer 1 which is opposed to the protruded streak 3, to the contrary, in this fastening device of the electric cable terminal.