To achieve a safe and sure elevator control operation, by easily and economically detecting small but long-period vibration having risk of causing an accident by swinging of a rope.

A vibration size is sensed at three levels by using an existing vibration detector 17 in a building, and first to third vibration detecting signals 101 to 103 are transmitted to an elevator control device 16. The elevator control device unconditionally performs second and third control operations when receiving second and third vibration detecting signals 102 and 103 of detecting large vibration. While, when receiving the first vibration detecting signal 101 of detecting small vibration, first control operation is performed by determining as the long-period vibration by receiving the first vibration detecting signal 101 again by exceeding the preset time.

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