A method for analyzing noise spectrum of an electronic device includes storing a waveform data including a plurality of data points, the waveform data is obtained by measuring a target signal from the electronic device, removing data points corresponding to a background noise fluctuation based on a smooth curve of the waveform data, data points considered candidates for peaks are extracted from the waveform data, classifying the extracted data points based on a distance between adjacent data points in order to discriminate a cluster of distant data points from data points closely positioned to dominant peaks, determining the dominant peaks based on the cluster of distant data points such that the data points closely positioned to the dominant peaks are ignored, each dominant peak corresponds to the characteristic of the electronic device, and outputting the dominant peaks as an analysis result for the electronic device.