THROUGH-HOLE SEALING STRUCTURE AND SEALING METHOD, AND TRANSFER SUBSTRATE FOR SEALING THROUGH-HOLE

A sealing structure including: a set of base members forming a sealed space; a through-hole which is formed in at least one of the base members, and communicates with the sealed space; and a sealing member that seals the through-hole. An underlying metal film including a bulk-like metal such as gold is provided on a surface of the base member provided with the through-hole. The sealing member seals the through-hole while being bonded to the underlying metal film, and includes: a sealing material which is bonded to the underlying metal film, and includes a compressed product of a metal powder of gold or the like, the metal powder having a purity of 99.9% by mass or more; and a lid-like metal film which is bonded to the sealing material, and includes a bulk-like metal such as gold. Further, the sealing material includes: an outer periphery-side densified region being in contact with an underlying metal film; and a center-side porous region being in contact with the through-hole. The densified region has a porosity of 10% or less in terms of an area ratio at any cross-section.