本研究旨在探討證券商在經營業務時，其業務人員因執行職務不法侵害客戶權益，證券商作為僱用人依民法第188條應負擔連帶損害賠償責任之範圍與實務運作。研究目的在於歸納學說與實務對於「執行職務」之認定標準，分析法院如何平衡被害人保護與僱用人責任，並藉此檢視證券商內部管理制度之有效性，以降低賠償責任及法律風險。 資料來源包含我國金融主管機關之法令、相關函釋、學者針對民法第188條之學術論著、期刊、學位論文以及國內外相關立法與理論。研究方法則採行文獻整理分析、比較分析研究及大量的案例與實務判決進行類型化研究。 研究結果發現，「執行職務」之認定早期實務多採「客觀說」及「行為外觀理論」。然而，近年判決出現限縮傾向，考量被害人是否明知或可得而知受僱人非執行職務。選任監督義務標準嚴苛，法院對民法第188條第1項但書之免責事由採嚴格標準，證券商僅依法規宣導等形式證據往往不足，導致該條於實務上趨向於無過失責任。與有過失之適用，法院多肯定依與有過失原則減輕證券商賠償比例，若投資人具專業經驗卻違反交易常規，應自負部分責任。 文末提出本研究建議，證券商應從形式遵循轉向實質監督，藉以實務判決歸納實質落實之方式，投資人亦應負起自我保護責任，最後對我國法制環境提出期待。;This study examines the scope and practical application of joint and several liability for damages imposed on securities firms as employers under Article 188 of the Civil Code， where their employees， in the course of performing their duties， unlawfully infringe upon clients’ rights and interests. The purpose of this research is to synthesize both academic theories and judicial practice regarding the criteria for determining the “performance of duties，” to analyze how courts balance the protection of victims with employer liability， and to evaluate the effectiveness of internal management systems within securities firms in mitigating liability and legal risks. The sources of this study include laws and regulations promulgated by Taiwan’s financial supervisory authorities， relevant administrative interpretations， academic publications， journal articles， theses and dissertations， as well as related domestic and foreign legislation and legal theories. The research methods employed consist of literature review and analysis， comparative analysis， and typological analysis based on a substantial number of cases and judicial decisions. The findings indicate that earlier judicial practice generally held that an employer should be held liable so long as the employee’s conduct， viewed objectively or based on its outward appearance， was sufficient to lead others to reasonably believe that it was related to the performance of duties. However， recent court decisions have taken into account whether the victim knew or should have known that the employee was not acting within the scope of employment. Courts adopt a strict standard in recognizing the exemption under the proviso to Paragraph 1 of Article 188 of the Civil Code， and securities firms often find that merely providing formal evidence such as regulatory compliance training is insufficient to establish exemption. Furthermore， where investors possess professional experience yet act in violation of standard trading practices， they should bear a portion of the responsibility. Finally， this study suggests that securities firms should shift from formal compliance to substantive supervision， drawing on judicial practice to identify effective implementation measures. Investors should also assume responsibility for self-protection. The study concludes with reflections and expectations regarding the development of Taiwan’s legal environment.
