Administrative actions should protect legitimate and reasonable trust of people. The principle of trust-based protection has three elements: 1. Basis for trust: When a person asserts that her reasonable trust should be protected, there must be a basis for trust where the administrative agency appears to have expressed out its state intent, or where there exists a factual act. 2. Trust-based behavior: Because of trust, a person starts to perform acts based on such trust, for example, to utilize her property or arrange her property for another deal, so as to create a change in terms of law. 3. Trust that deserves protection: If a beneficiary is honest and does not make false statements, the right or interest of such person will be harmed when the administrative agency later wants to remove such basis of trust. The trademark revocation system in our country is to renew the examination through public examination or examination by duty to find whether the registration of a trademark involves any reason under the law for denying registration. As a result, when Plaintiff applied for the trademark at dispute, later invalidation by a revocation is deemed to be expectable. In addition, Plaintiff had known that the place of the origin of Sanuki-shi wu-long noodles is Sanuki-shi region in Japan. So, the principle of trust-based protection cannot be asserted.

Principle of trust-based protection, administrative action, trademark revocation, public examination, examination by duty