To provide a bed device which is attached to the mattress of a bed to add functions same as conventional metallic side frames including various functions of a small article container, etc., to make bed life more comfortable.

The mattress unit 6 of a mattress 3 laid on a bottom has head units 6h, 6h', foot units 6f, back flank units 6s1, 6s1', and foot flank units 6s2. The head units 6h, 6h' and back flank units 6s1, 6s1', and foot units 6f, back flank units 6s1, 6s1' and foot flank units 6s2 are integrally placed respectively via corner units 6c. A hollow part R is formed as a small article container in the head unit 6h' and the upper part projected from the upper face of the mattress 3 is made a lid member 7 for surrounding the hollow part R. A slit S is formed in the back flank unit 6s1' so that a tissue box Tb is housed in the lid member 7 of to cover the hollow part R to enable a user to take out tissue via the lid member 7.