The DNA origami technique is a recently developed self-assembly method that allows construction of 3D objects at the nanoscale for various applications. In the current study we report the production of a 18 × 18 × 24 nm(3) hollow DNA box origami structure with a switchable lid. The structure was efficiently produced and characterized by atomic force microscopy, transmission electron microscopy, and Förster resonance energy transfer spectroscopy. The DNA box has a unique reclosing mechanism, which enables it to repeatedly open and close in response to a unique set of DNA keys. This DNA device can potentially be used for a broad range of applications such as controlling the function of single molecules, controlled drug delivery, and molecular computing.