To provide a bed capable of instantaneously reducing the humidity and temperature of circum-ambient air around a user's body and retaining the reduced humidity for a long period of time.

This bed comprises a mat having air permeability and nonhygroscopic property, a base part for mounting the mat, and leg parts supporting the base part for forming a space between the base part lower face and a floor face; and is characterized in that the base part has a base formed into a box shape having an opening part in its upper face and a plurality of flat plate materials extending in the bed width direction, crossing the opening part of the base and having the hygroscopic property and moisture-releasing property, the plurality of flat plate materials are disposed in parallel to each other at a prescribed interval apart, the inside space formed between the flat plate materials and the base inner bottom face is disposed with a fan, and the fan downward exhausts the air in the inside space via the opening part formed in the base bottom part.