NOVELTY - The device for the combined production of hydrogen (23) and methane by fermentation of biological starting materials (1), comprises a first fermentation container (15), in which first micro organisms and biological starting materials as a metabolism product are contacted under such process conditions to form hydrogen, and units for discharge of liquid conversion products from the first fermentation container and for restraint of micro organisms. The units have a gasifier for supplying of air at the base of the first fermentation container.    USE - Device for the combined production of hydrogen and methane by fermentation of biological starting materials (claimed).    ADVANTAGE - The device has high durability and ensures effective production of hydrogen and methane by fermentation of biological starting materials.    DETAILED DESCRIPTION - The device for the combined production of hydrogen (23) and methane by fermentation of biological starting materials (1), comprises a first fermentation container (15), in which first micro organisms and biological starting materials as a metabolism product are contacted under such process conditions to form hydrogen, and units for discharge of liquid conversion products from the first fermentation container and for restraint of micro organisms. The units have a gasifier for supplying of air at the base of the first fermentation container. The liquid conversion products from the first fermentation container are supplied to a second fermentation container, in which second microorganisms and biological starting materials as a metabolism product are contacted under such process conditions to form methane. The first fermentation container has units for the mixing of the biological starting materials and for the supply of air (17) into the biological starting materials. The first fermentation container has units for adjusting the process conditions, for the heating of the biological starting materials and for the default of the pH value of the biological starting materials. The units are controllable for the supply of air for an adjustment of aerobic or anaerobic process conditions in the first fermentation container. The units have a rinsed filter for the restraint of the first microorganisms in the first fermentation container.    DESCRIPTION OF DRAWING(S) - The drawing shows a device for the combined production of hydrogen and methane.    Biological starting materials (1)    Grinder (3)    First fermentation container (15)    Air (17)    Hydrogen. (23)