A liquid discharge head comprising: a channel member including: a nozzle surface parallel to a first direction and a second direction orthogonal to the first direction; a plurality of first nozzles (21; R2, R3) aligned in the first direction in the nozzle surface; a plurality of second nozzles (21: R4, R5) aligned in the first direction in the nozzle surface and arranged side by side to the plurality of first nozzles (21; R2, R3) in the second direction; a first common channel extending in the first direction and communicating with the plurality of first nozzles (21; R2, R3); a second common channel extending in the first direction, arranged side by side to the first common channel in the second direction, and communicating with the plurality of second nozzles (21; R4, R5); and a film member including a first surface and a second surface, the first surface defining the first common channel and the second common channel, being parallel to the first and second directions, the second surface being located on an opposite side to the first surface in a third direction orthogonal to the first and second directions, and being parallel to the first and second directions, wherein the second surface includes a first recess overlapping with the first common channel in the third direction, and a second recess overlapping with the second common channel in the third direction, and wherein a length of the first recess in the second direction is different from a length of the second recess in the second direction; the liquid discharge head characterised in that a length of the first common channel in the second direction is substantially same as a length of the second common channel in the second direction. a channel member including: a nozzle surface parallel to a first direction and a second direction orthogonal to the first direction; a plurality of first nozzles (21; R2, R3) aligned in the first direction in the nozzle surface; a plurality of second nozzles (21: R4, R5) aligned in the first direction in the nozzle surface and arranged side by side to the plurality of first nozzles (21; R2, R3) in the second direction; a first common channel extending in the first direction and communicating with the plurality of first nozzles (21; R2, R3); a second common channel extending in the first direction, arranged side by side to the first common channel in the second direction, and communicating with the plurality of second nozzles (21; R4, R5); and a film member including a first surface and a second surface, the first surface defining the first common channel and the second common channel, being parallel to the first and second directions, the second surface being located on an opposite side to the first surface in a third direction orthogonal to the first and second directions, and being parallel to the first and second directions, a nozzle surface parallel to a first direction and a second direction orthogonal to the first direction; a plurality of first nozzles (21; R2, R3) aligned in the first direction in the nozzle surface; a plurality of second nozzles (21: R4, R5) aligned in the first direction in the nozzle surface and arranged side by side to the plurality of first nozzles (21; R2, R3) in the second direction; a first common channel extending in the first direction and communicating with the plurality of first nozzles (21; R2, R3); a second common channel extending in the first direction, arranged side by side to the first common channel in the second direction, and communicating with the plurality of second nozzles (21; R4, R5); and a film member including a first surface and a second surface, the first surface defining the first common channel and the second common channel, being parallel to the first and second directions, the second surface being located on an opposite side to the first surface in a third direction orthogonal to the first and second directions, and being parallel to the first and second directions, the first surface defining the first common channel and the second common channel, being parallel to the first and second directions, the second surface being located on an opposite side to the first surface in a third direction orthogonal to the first and second directions, and being parallel to the first and second directions, wherein the second surface includes a first recess overlapping with the first common channel in the third direction, and a second recess overlapping with the second common channel in the third direction, and wherein a length of the first recess in the second direction is different from a length of the second recess in the second direction; the liquid discharge head characterised in that a length of the first common channel in the second direction is substantially same as a length of the second common channel in the second direction.