A sealing structure comprising: a set of base materials forming a sealed space; at least one through-hole which is formed in at least one of the set of base materials, and communicates with the sealed space; and a sealing member that seals the through-hole, wherein the sealing structure comprises an underlying metal film on a surface of the base material in which the through-hole is formed, the underlying metal film comprising a bulk metal consisting of at least one of gold, silver, palladium and platinum, the underlying metal film being formed so as to surround the peripheral part of the through-hole, the sealing member seals the through-hole while being bonded to the underlying metal film, the sealing member comprises: a sealing material which is bonded to the underlying metal film, and consists of a compressed product of a metal powder sintered body obtained by sintering a metal powder consisting of gold having a purity of 99.9% by mass or more; and a lid-like metal film which is bonded to the sealing material, and comprises a bulk metal consisting of gold at least at a surface that is in contact with the sealing material, the bulk metal having a thickness of not less than 0.01 μm and not more than 5 μm, the sealing material comprises: an outer periphery-side densified region that is in contact with the underlying metal film; and a center-side porous region that is in contact with the through-hole, and a horizontal length I of a pore in a radial direction at any cross-section of the densified region and a width W of the densified region satisfy the relationship of I ≤ 0.1W. a set of base materials forming a sealed space; at least one through-hole which is formed in at least one of the set of base materials, and communicates with the sealed space; and a sealing member that seals the through-hole, wherein the sealing structure comprises an underlying metal film on a surface of the base material in which the through-hole is formed, the underlying metal film comprising a bulk metal consisting of at least one of gold, silver, palladium and platinum, the underlying metal film being formed so as to surround the peripheral part of the through-hole, the sealing member seals the through-hole while being bonded to the underlying metal film, the sealing member comprises: a sealing material which is bonded to the underlying metal film, and consists of a compressed product of a metal powder sintered body obtained by sintering a metal powder consisting of gold having a purity of 99.9% by mass or more; and a lid-like metal film which is bonded to the sealing material, and comprises a bulk metal consisting of gold at least at a surface that is in contact with the sealing material, the bulk metal having a thickness of not less than 0.01 μm and not more than 5 μm, the sealing material comprises: an outer periphery-side densified region that is in contact with the underlying metal film; and a center-side porous region that is in contact with the through-hole, and a horizontal length I of a pore in a radial direction at any cross-section of the densified region and a width W of the densified region satisfy the relationship of I ≤ 0.1W. a sealing material which is bonded to the underlying metal film, and consists of a compressed product of a metal powder sintered body obtained by sintering a metal powder consisting of gold having a purity of 99.9% by mass or more; and a lid-like metal film which is bonded to the sealing material, and comprises a bulk metal consisting of gold at least at a surface that is in contact with the sealing material, the bulk metal having a thickness of not less than 0.01 μm and not more than 5 μm, the sealing material comprises: an outer periphery-side densified region that is in contact with the underlying metal film; and a center-side porous region that is in contact with the through-hole, and a horizontal length I of a pore in a radial direction at any cross-section of the densified region and a width W of the densified region satisfy the relationship of I ≤ 0.1W. an outer periphery-side densified region that is in contact with the underlying metal film; and a center-side porous region that is in contact with the through-hole, and a horizontal length I of a pore in a radial direction at any cross-section of the densified region and a width W of the densified region satisfy the relationship of I ≤ 0.1W.