An incubator comprises an incubator chamber defined by a bottom part and a top casing covering a bed area of the bottom part. The incubator comprises an air treatment and circulation device for treating air and circulating it through the chamber, said air treatment and circulation device including a ventilator. The air treatment and circulation device is connected to chamber inlet openings which are arranged along one or more sides of said bed area, allowing treated air to flow from the treatment and circulation device into the chamber. The air treatment and circulation device furthermore is connected to at least one chamber outlet opening allowing air to flow out from the chamber to the treatment and circulation device. The air flows in the incubator are routed such that noise is reduced and no high air flow speeds occur near the infant in the incubator.