An inflatable bed includes a bedstead assembly, a mattress assembly, and an electrical air pump unit. The mattress assembly is disposed on and above the bedstead assembly, and includes a top sheet, a bottom sheet disposed under the top sheet, and a plurality of surrounding sheets interconnecting the top and bottom sheets to form a plurality of air chambers, which are not in fluid communication with each other. Each of the air chambers is defined among the top sheet, the bottom sheet, and a respective one of the surrounding sheets. The electrical air pump unit is disposed on the bedstead assembly, and is operable to inflate the air chambers individually so that air pressures in the air chambers may be different.