A method of cleaning a food plant of the type which produces an aseptic product or a product with extended shelf life involves at least one circulation with an alkaline detergent solution and at least one circulation with an acidic cleaning solutions. The circulations take place alternatively with the alkaline detergent solution and the acidic cleaning solution. Prior to the first circulation, between each circulation and after the last circulation, rinsings with water take place. Simultaneously with the last circulation with alkaline detergent solution the plant is sterilized, and after the last circulation with the acidic cleaning solution the two last rinsings with water take place with sterile liquid.