To provide a storage bed having a storage part, and compose this to be usable as a sofa.

This device comprises a storage part 3 comprising an up-opened box main body 1 of a specified height H, and a cover 2 of a specified thickness T attached on the box main body 1 to be freely opened/closed. A middle floor part 4 of a specified axial length L is pivotally connected to a back end edge of the storage part 3 to be unfolded flat or raised vertically. A back floor part 5 of a roughly similar size to a total size of the specified height H, the specified thicknes T and the specified length L is pivotally connected to a back end edge of the middle floor part 4 to be horizontally unfolded or vertically raised.