The invention provides an elevator device capable of high-precision sensing the swaying of the strip components such as the main rope to perform the control operation when the earthquake happens. The strip component in an elevator hoist trunk (20) such as the main rope (7) sets a plurality of natural periods and the relative displacement of the main rope (7) relative to the displacement of the hoist trunk (20) is calculated according the signals detected by a vibrograph (5) in the buildings or the hoist trunk (20), direct towards each natural period and at the same time the calculated result is compared with the preset threshold to judge whether the control operation is performed or not.