政府為了提升國家及產業的競爭力，特制定租稅獎勵法規以獎勵投入研發與設備、技術改良之產業與企業，而其中最具代表性的租稅獎勵法規即為「促進產業升級條例」。「產升條例」自施行以來已損失鉅額稅收，尤其「產升條例」中第六條的投資自動化機器設備、研究發展、人才培訓之投資抵減項目，該項目之抵減稅額約占總抵減稅額的百分之三十，堪稱是最重要的租稅獎勵措施，因此本研究特以「產升條例」第六條之投資抵減為研究範圍，以探討政府所提供的投資抵減租稅獎勵政策對於提升企業的經營績效是否有具體影響？ 本研究以民國87年度至93年度之上市櫃電子及電機公司為研究對象，採用資料包絡分析方法計算效率值，再以是否取得投資抵減為分類，運用單變項無母數方法檢定效率值，比較有無投資抵減與經營績效之間的差異，最後以Tobit迴歸控制各項公司特性與總體產業因素進一步探討投資抵減對企業經營效率之影響。 本研究實證結果發現，不論是電子業或電機業，均顯示投資抵減政策確實使得公司降低成本，但是未能明顯提升公司的技術效率。在Tobit迴歸分析中的電子業部分，實證結果顯示投資抵減並不是提升公司經營效率的關鍵影響因素，若公司過於依賴租稅減免，反而不利於改進其成本效率；在電機業部分，實證結果顯示投資抵減獎勵沒有達成政府預期的效果，因此電子業與電機業有同樣之現象：企業過度依賴租稅減免，而未致力於技術水準之提升。 / In order to strengthen the competitiveness of the nation and industries, the government has instituted the related regulations to stimulate the R&D input, equipment investment, and technology improvement of companies. One of the most representative regulations is “Statute for Upgrading Industries,” especially the Article six of which, the most important tax measure, referring to invest in automatic equipment, R&D, and personnel training and resulting in huge number of losses of tax revenue. The number of investment credit against tax in accordance with the Article six accounts for thirty percent of the total investment tax credit. Therefore, the Article six of “Statute for Upgrading Industries” is chosen as the research topic of this thesis. The research goal is to review whether corporate operating efficiencies are influenced concretely by this tax measures. We sample the several listed companies in the electric industry and in the electrical machinery industry as our research targets, and choose DEA to calculate the efficiencies of companies classified by the applicability of investment tax credit. Finally, we utilize statistical methods to research the relationship between investment tax credit and corporate efficiencies. In our empirical study, we find that the companies, in both electric industry and electrical machinery industry, eligible for investment tax credit, have higher allocation efficiency, but those unqualified for investment tax credit have higher cost efficiency and pure technical efficiency. This result indicates that the policy of investment tax credit is able to help companies reduce costs, but is unable to improve their technical efficiencies.