A mixer insert (1) for a static mixer, comprising a plurality of mixing elements (3, 3a, 3b, 3c, 3d, etc.) which are disposed one behind the other along a longitudinal axis (L) and preferably immediately adjoin each other and each comprise a plurality of crossing rods (8, 9; 10, 11), at least two mixing elements consecutive along the longitudinal axis (L) among the plurality of mixing elements (3, 3a, 3b; 3b, 3c; 3c, 3d; etc.) being turned relative to each other by a twist angle of preferably 90° with respect to the longitudinal axis (L), the mixer insert (1) being composed of multiple separate mixer-insert parts (2, 2a, 2b) which each extend along the longitudinal axis and which are disposed adjacent to each other perpendicular to the longitudinal axis (L), each mixer-insert part (2, 2a, 2b) having a plurality of mixing-element parts (14, 14a, 14b, 14c, 14d, etc.; 15, 15a, 15b, 15c, 15d, etc.) which are disposed one behind the other along the longitudinal axis (L) and are integrally connected to each other along the longitudinal axis (L) and immediately adjoin each other, and that the mixing-element parts (14, 15; 14a, 15a; 14b, 15b; 14c, 15c, 14d, 15d; etc.) of the mixer-insert parts (2, 2a, 2b) that are disposed next to each other perpendicular to the longitudinal axis form one of the mixing elements (3, 3a, 3b, 3c, 3d, etc.), and that at least two of the mixing-element parts (14, 14a, 14b, 14c, 14d, etc.; 15, 15a, 15b, 15c, 15d, etc.) of the mixer-insert parts (2, 2a, 2b) that immediately adjoin each other along the longitudinal axis (L) are turned relative to each other by the twist angle with respect to the longitudinal axis (L).