The purpose of this study was to reveal individuals' willingness to purchase a Prefilled Syringe Containing Influenza Vaccine Preparations, their willingness to pay, WTP, and other related factors.
　The survey was executed by using the contingent value method in medical facility where a Prefilled Syringe Containing Influenza Vaccine Preparations provides the vaccine for individuals.
　A web questionnaire was conducted to 269 individuals who lived across the country.
　As a result, it was indicated that 83.6％ of respondents showed willingness to purchase the vaccine：the mode for WTP was 500 yen, the average was 460 yen, and the median was 300 yen. There was also indicated significant relationship between WTP and their valuation of the vaccine.
　The willingness to purchase the vaccine was also related to household income and experience of influenza vaccine inoculation in the past one year. On the other hand, WTP was related to having a child and having enough in the family finances, but not to age, sex, marriage and chronic disease.