A thermal insulating structure includes: at least two first multilayer vacuum insulators that adjoin each other and that cover a to-be-insulated surface; a retainer that is fixed to the to-be-insulated surface and that protrudes from a boundary between the first multilayer vacuum insulators; a second multilayer vacuum insulator that extends along the boundary and that covers the boundary, the second multilayer vacuum insulator including a through-hole formed therein, in which the retainer is inserted; and a keep plate that is fixed to the retainer and that holds the second multilayer vacuum insulator and the first multilayer vacuum insulators.