購併能否帶給企業正面效果，向來皆是大眾所關注之議題，本研究特別由購併與非購併族群之績效比較來檢驗此一問題。我們針對國內電子產業於2004至2005年間從事購併事件之41間上市櫃公司為樣本，利用事件研究法檢驗購併宣告效果，再利用Fama and French（1993）三因子模型探討公司購併後之長短期績效，並與對應之非購併企業績效加以比較。本文更進一步對研究標的分類，檢驗電子業中相關族群及上市與上櫃電子公司購併後之長短期績效並加以比較。實證結論發現，宣告當天出現顯著的異常報酬，但亦有數天出現負的異常報酬與累積異常報酬，顯示市場對購併決策仍存有疑慮。公司在購併後3年期間內均未享有顯著股票異常報酬，且相對於非購併企業之股票報酬績效並無顯著差異。在進一步分類下，對於半導體公司或電子零組件公司，上市或上櫃公司，均無法反應出長短期購併績效。

The issue of whether corporate gain benefit from M&As has been a widely interested topic. This study explores this topic especially by comparing the performance of merging companies with that of non-merging companies. For 41 merging companies of electronic industry from the listed and OTC firms in Taiwan during 2004 and 2005, this study uses event study method to investigate the announcement effect of M&A activities. We also use Fama and French (1993) three-factor model to examine the long and short term merger performances (1 through 3years) and these results will be compared with that of non-merging companies. Furthermore, the merging performances will be examined further under different classification. The empirical results indicate that there are positive- and negative-significant-abnormal returns in the announcement period. This means that market investors doubt of the M&A activities. Besides, there are not significant stock abnormal returns in the 3 years for merging and non-merging firms. Under the further classification, there are not significant performances of mergers in the short and long terms for semiconductor companies or electronic component companies and listed or OTC companies.