According to the Supreme Court’s legal principles on the extinctive prescription for right of remuneration for employee invention, if there are no in-house employee invention regulations, or even if they exist, the time and procedure for payment of remuneration are not stipulated, the prescription proceeds from the time of succession of the invention and is completed early. In particular, this situation is harsh on employees who “did not know” that they could exercise the right to claim remuneration while the prescription was in progress and who “know” that they could exercise the right to claim remuneration only after the prescription was completed. Therefore, it is necessary to introduce a method of determining the starting point of the prescription based on the “subjective perception” of employees. Even if “10 years” have elapsed from the time of succession of the right to the invention or the time when the legal obstacle to the employee’s exercise of the right to claim remuneration has lapsed based on the Supreme Court’s legal principles, the prescription is completed only after “10 years” has elapsed “from the time when the employee knew or could know” that the employee could exercise the right to claim remuneration. This improvement plan is a “good way” to protect employees.