To provide a platformed mattress that can prepare functions particularly required for bed users such as patients at low cost, and facilitates customizing the most suitable mattress according to each bed user, and to provide a method for using the same. A lower mattress member 1 has necessary functions as a mattress on a bed, includes commonly necessary functions for bed users such as various patients, has minimum feeling in bed, and has the function as the mattress for the patient lying thereon with that alone. Also, upper mattress members (10, 20) have the functions to be added or increased according to characteristics of the bed users such as patients, namely the functions necessary for individual bed user but not obtained only by the lower mattress member. Then, the lower mattress member (1) and the upper mattress members (10, 20) are stored in a cover and integrated, and used as the mattress.
