The present invention provides a box-shaped soundproof structure that is compact, lightweight, and capable of sufficiently reducing noise having a frequency specific to a sound source. The box-shaped soundproof structure includes a box body that is open at least in part thereof and a muffler structure including a resonator disposed inside the box body. The muffler structure reduces sound generated by a sound source disposed in contact with the outer wall of the box body or inside the box body and released to the outside via the open face of the box body.