In principle, a patent application will be laid open after one year and six months from a filing date. Where an applicant does not wish to have an invention known to another person by laying-open, the applicant may file a request for withdrawal of the application to the Japanese Patent Office to avoid laying-open. However, in case that the applicant requests it near the date of laying-open, the application is nevertheless to be laid open. This is because the Japanese Patent Office begins to make preparation of the laying-open three months before the date of the laying-open. After this date, the preparation cannot be stopped as a rule. Thus, please note that the request for withdrawal of the application is completed three months at the latest in advance of the date of the laying-open in order to ensure to stop it.