A method for producing an absorbent structure (10, 10') for absorbent sanitary articles, comprising the steps of: - advancing a first non-woven layer (12, 12') at a first speed (V1), with a first surface (18) of said first non-woven layer (12, 12') facing a suction chamber (28), - distributing superabsorbent granular material (14, 14') on a second surface (20) of said first non-woven layer (12, 12') opposite to said first surface (18), - volumizing said first non-woven layer (12, 12') by means of a toothed portion (38, 50) that penetrates into said first non-woven layer (12, 12') through said second surface (20) and movable with respect to said first non-woven layer (12, 12') with a speed difference (”V).
