The invention relates to an air mattress (1) comprising a number of successive, elongate and bag-like elements, which can be filled with gas such as air or with some other flowing medium. The elements are ar­ranged transversally with respect to the lengthwise axis (D - D) of the mattress and/or the bed, and are connected to each other successively in a band-like fashion. The successive elements (2, 2′) are arranged so that the lenghtwise seam joints (6; 6b) of the ele­mentes are located at given intervals in the bottom part (1b) of the mattress, and that the areas between these seam joints are arranged to form structures which are directed upwards from the bottom part (1b) of the mattress.
The invention also relates to a method for adjusting an air mattress or the like. The elements (2, 2′; 9, 10) of the mattress are partly filled with for instance air, so that the mattress pressure cor­responds to the pressure of the surroundings when the mattress elements are not subjected to a weight load, but the mattress pressure grows in a known fashion according to the weight load of the human body or part thereof, so that the mattress elements conform to the contours of the body or part thereof, and simultaneously the surface pressure against the body or part thereof is distributed evenly over the whole body or part there­of.