Abstract: An incubator includes: a housing which is divided into a thermostatic chamber and an air-conditioning chamber and allows first air to circulate between the thermostatic chamber and the air-conditioning chamber; and an air conditioner that regulates a temperature of the first air in the air-conditioning chamber. A channel through which the first air flows is formed in the air-conditioning chamber. The air conditioner includes: a supply unit having a supply port for supplying second air colder than the first air to the channel; an upstream fan which is arranged upstream of the supply port and allows the first air in the thermostatic chamber to flow into the channel; and a downstream fan which is arranged downstream of the supply port, mixes the second air with the first air, and allows the first air mixed with the second air to flow from the channel into the thermostatic chamber.