Model 3 shows the impacts of the structural variables on beliefs in conspiracy theories. Knowledge and the quality of information positively affect these beliefs, whereas the amount of information, health status, and worsening health status after COVID-19 have negative impacts. Education level, income, gender, and age have no statistically significant effects. The first important point is about to the roles of education and knowledge. The former does not affect beliefs in conspiracy theories, whereas the latter does affect them. These results suggest that rather than increasing formal education, a knowledge-centered approach is needed to reduce beliefs in COVID-19 conspiracy theories. Second, the quality and quantity of information perform opposite functions. The former decreases beliefs in conspiracy theories, whereas the latter increases such beliefs. This result implies that the large quantities of information available on SNS contain conspiracy theories, suggesting that high-quality information is needed to address the large quantities of information about conspiracy theories. Third, the two health variables have opposite effects. Generally, health increases beliefs in conspiracy theories, but a deterioration in health after COVID-19 leads to stronger beliefs in conspiracy theories. The information quality variable has the greatest explanatory power in Model 3, followed by health status, the quantity of information, and health status after COVID-19. The results confirm the importance of information and health.