Occurring economic loss of economics by the earthquake, such as Gyeongju and Pohang in Korea, interest in seismic stability of facilities is increasing. Electrical Cabinet Structure in Power Plant should be prepared for malfunctions and its structural safety should be ensured as well an earthquake event. The purpose of this investigation is to increase the seismic stability of the cabinet. Through finite elements analysis, dynamic characteristics of the cabinet were identified herein, and time history analysis was performed by converting the design response spectra. In order to improve safety against earthquakes, a variable analysis was conducted to utilize steel dampers for seismic retrofit of the cabinet, and time history analysis results compared with the response of basic and seismic retrofitted cabinets.