Abstract: A button cover holding mechanism in which an angle between a button cover and a body is constantly maintained when the button cover of a portable telephone is in an open condition, and the button cover is maintained in a closed condition when the portable telephone is in the closed condition, which is more convenient for a user to open and close the button cover. The button cover holding mechanism of a portable telephone has a cylindrical bush, a cylindrical ring and a spring inserted into circular holes of a button cover, covered with a cover mounting projection, and sealed by an ultrasonic connection technique; such that an opposite cylindrical ring is inserted into a reception guide rail of a body by positioning the cylindrical bush of the button cover toward a projection bar of the body, and the cylindrical bush and the cylindrical ring are outwardly positioned by a restoring force of the spring so that a trough portion of the cylindrical bush is assembled in contact with the projection bar.