To prevent generation of disconnection and connection failure of cable due to rotation thereof and provide cable fixing structure having excellent water-tight property.

A clamping plate 13 is provided with a different shape hole 13a which is different in the shape from a circular cross-sectional shape. A cable gasket 12 is compressed between the clamping plate 13 and the internal surface of a recessed portion 11b when a clamping screw 14 is tightened and is deformed depending on the shape of the different shape hole 13a. The cable 1 is fixed because it catches the cable gasket 12 deformed in the different shape.