A hinge shaft 6 is nonpivotably connected to a cover 3. Two shaft portions 63 are formed on the hinge shaft 6. Spring elements 51, which are nonpivotably disposed at a telephone main body 2, are in pressure contact with the shaft portions 63. By the foregoing arrangement, the shaft portions 63 are functioned as a pivotal movement restricting portion for restricting a pivoting position of the cover 3. The shaft portions 63 are arranged away from each other so that a space S for storing a lubricating oil such as a grease is formed therebetween.