Provided is a vacuum insulator having both an excellent insulating performance and an excellent bending strength. A vacuum insulator (1) is configured by a sack-shaped enveloping member (3) and at least one sheet (7) including a plurality of inorganic fibers and includes a core member (5) enclosed in the enveloping member (3). The sheet (7) includes a plurality of bundled inorganic fibers (9) formed by bundling some inorganic fibers from among the plurality of inorganic fibers. At least a part of the bundled inorganic fibers (9) are in contact with each other.
