PROBLEM TO BE SOLVED: To provide an air cell unit which can enhance a reduction in a contact surface pressure by increasing an area for supporting a supporting subject, a mattress, a cushion, and a nursing care robot.SOLUTION: An air cell unit includes: a first air cell 10 where a first sheet 11 and a second sheet 12 which are overlapped with each other and are bonded at the circumferences for forming a gas layer are firmly fixed at a first firmly fixing part 13 a second air cell 20 where a third sheet 21 and a fourth sheet 22 which are overlapped with each other and are bonded at the circumferences for forming a gas layer are firmly fixed at a second firmly fixing part 23 and an intermediate layer 30 which connects the first air cell 10 and the second air cell 20 in a manner to be overlapped with each other and to be relatively movable in a direction perpendicular to an overlapped direction and where the first air cell 10 and the second air cell 20 are separated while a part between the first air cell and the second air cell communicates with ambient air. The first firmly fixing part 13 and the second firmly fixing part 23 are arranged to be staggered.SELECTED DRAWING: Figure 3
