An air mat (20) includes cells (21, 22, 23) arranged in a longitudinal direction of the air mat. Each cell (21, 22, 23) is bag-shaped and made of a plastic sheet. Each cell (21, 22, 23) includes an air supply port (21a, 22a, 23a) for supplying air into the cell. The cells (21, 22, 23) include at least one specific cell (S) that corresponds to the buttocks (G) of a user (U) and non-specific cells (NS) other than the specific cell (S). The air mat (20) further includes a first air supply system (60) that is connected to the air supply port of the specific cell (S) to supply air to the specific cell (S) and a second air supply system (70) that is connected to the air supply ports of the non-specific cells (NS) to supply air to the non-specific cells (NS).
