To provide a stackable simple bed which is constituted by spreading a sheet in between a long longitudinal element and lateral element mutually combined by corner elements to form a square frame as a whole.

Each corner element (2) is equipped with a leg (6) on the downside and a vertical dent part (7) aligned with the leg (6) on the up side. The dent part (7) is used to accept a leg (6) of another same type bed stacked on the bed. Each corner element (2) has an upper part (10) and a lower part (11) to be mutually combined. The dent part (7) is formed in the upper part (10) which is opened outward, extended sufficiently along a whole of the height, and equipped with a vertical slot shape side opening opened upward.