A device for supplying breathing air to a breathing air region has an air purification unit with filter unit and blower unit. First areal outflow regions with air outlet openings and having a first surface area are provided. The air purification unit supplies breathing air to the first areal outflow regions and the breathing air flows out in an outflow direction. Areal boundary devices with a second surface area are provided. The areal boundary devices are arranged opposite the first areal outflow regions such that each first areal outflow region has one of the areal boundary devices positioned opposite thereto at an angle of less than 10°. The second surface area of the areal boundary device corresponds at least to the first surface area of the first areal outflow region. The breathing air region is located between the areal boundary device and the first areal outflow region.