An elastic structure for absorbent sanitary products, comprising- a sleeve (12) comprising a first and a second layer (14, 16) overlapping each other,- at least one elastic thread (18), which extends within said sleeve (12) in a longitudinal direction, and- a plurality of first connecting portions (24) spaced apart in the longitudinal direction, wherein each of said first connecting portions (24) comprises two first welds (28) arranged on opposite sides of the thread (18), wherein the first welds (28) weld said first and said second layers (14, 16) to each other in a first longitudinal portion (20) of said sleeve (12), and wherein said first welds (28) of each of said first connecting portions (24) have respective proximal surfaces (30) facing the thread (18), spaced apart by a distance (D1) less than the diameter (D) of the untensioned thread, in order to anchor the thread (18) to said first longitudinal portion (20) of the sleeve (12), and- a plurality of second connecting portions (26) spaced apart in the longitudinal direction, wherein each of said second connecting portions (26) comprises at least one second weld (29), wherein said second welds (29) weld said first and said second layers (14, 16) to each other in a second longitudinal portion (22) of said sleeve (12) without axially connecting the thread (18) to said second longitudinal portion (22) of the sleeve (12).