The authors have previously conducted studies on a technology that allows the estimation of mental state based on the voice and developed a smartphone system to monitor mental health status using voice during telephone calls. In this study, the effectiveness of this voice-based method was validated in the voices passed through the Web meeting systems often used in recent years. Our method was applied to the voices from the Web meeting systems and the original voices. The correlation between the two analysis results was investigated. Significantly strong positive correlations were found between the results of the voices through the Web meeting systems and the original voices. Therefore, the effectiveness of our method in estimating mental health using the Web meeting systems was suggested.