A method for forming a three-dimensional object in a forming apparatus, wherein a natural fibre-based substance in the form of a sheet material enters the forming apparatus through an inlet and wherein a three-dimensional object made with the natural fibre-based substance exits the forming apparatus through an outlet, a path connecting the inlet and the outlet, wherein the sheet material is cut in a cutting unit positioned along said path, in order to separate a dose of natural fibre-based substance from the sheet material, and wherein the three-dimensional object is formed by pressing the dose between a female half-mould and a male half-mould of a pressing unit, the pressing unit being positioned along said path downstream of the cutting unit.