A chair includes a backrest, a seat and legs. The seat includes a cushion formed with a net-like structure made of a thermoplastic resin and having a thickness, a seat plate configured to support the cushion, and an outer covering configured to cover the cushion. An upper surface of the cushion includes a first place that has a first hardness and that is configured to support a sitting person's buttock, a second place that is located outside of the first place when seen in a plan view and that has a second hardness higher than the first hardness, and a third place that is located outside of the second place when seen in a plan view and that has a third hardness higher than the second hardness.