In this research, we investigate users' subjective sense of security, which we call Anshin in Japanese. The research goal is to create a guideline of Anshin in information security for users. In this paper, we report how the user security knowledge level could influence the factors of Anshin for online shopping users. Traditional studies on security have been based on the assumption that users would feel the sense of security when provided with objectively secure systems. We conducted a Web survey with 920 subjects with our questionnaire. We divided the subjects into two groups which have low and high security knowledge level and analyzed each group. Then, we divided each group into two sub-groups and compare the result. As a result of the analysis, we extracted the similar factors between them. However, we found a difference between the two sub-groups in high security knowledge level groups. As a result, we conclude that there are different Anshin factors in accordance with the user security knowledge level. Moreover, we showed that Anshin factors might also affect other attributes when user security knowledge level is high.