The present invention provides a shipping method for guaranteeing that an article for shipping has remained sealed with a seal and has remained unopened. Specifically, first, the sender is asked to enter a signature on a seal. Because of the pressure from a writing implement at time of entering, the signature is copied to a sheet for verification. An article for shipping is sealed with a seal and transported to a recipient. The signature on the seal is verified against the signature on the sheet for verification. By confirming that the two match, it is confirmed that the seal has not been replaced. Thus it is guaranteed that the article for shipping has remained sealed with the seal and has remained unopened.