A laser amplification device (200; 500; 600; 700), which comprises: - an amplification element , consisting of a doped amplifying plate (213; 313) and two non-doped end bars (2141, 2142; 3141, 3142), the end bars laterally surrounding the amplifying plate, and each end bar having a face, located on the side opposite to the amplifying plate, which forms an inlet face (611; 711), respectively an outlet face (212; 612; 712) of the amplification element for a laser beam to be amplified ; and - two temperature control systems (230A, 230B; 630A, 630B), respectively covering an upper face and a lower face of the amplification element, the upper, respectively lower, face of the amplification element consisting of the upper faces, respectively lower faces, of the amplifying plate and of the two end bars, where - each temperature control system (230A, 230B; 630A, 630B) comprises a cooling element (231A; 231B; 431 1 ; 431 2 ; 431 3 ; 431 4 ; 431 5 ; 531A), covering a centre region of the upper, respectively lower, face of the amplification element, characterised in that - each temperature control system further comprises at least one heating element (232A; 232B; 432 1 ; 432 2 ; 432 3 ; 432 4 ; 432 5 ; 532B), covering peripheral regions of the upper, respectively lower, face of the amplification element; and - the temperature control systems (230A; 230B; 630A; 630B) are substantially symmetrical to each other, according to an orthogonal symmetry with respect to a plane (P), said plane (P) being a plane parallel to the upper and lower faces of the amplifying plate (213; 313) and passing through said plate, and each temperature control system having a recovery rate higher than 90% with the symmetrical part of the other temperature control system. - an amplification element , consisting of a doped amplifying plate (213; 313) and two non-doped end bars (2141, 2142; 3141, 3142), the end bars laterally surrounding the amplifying plate, and each end bar having a face, located on the side opposite to the amplifying plate, which forms an inlet face (611; 711), respectively an outlet face (212; 612; 712) of the amplification element for a laser beam to be amplified ; and - two temperature control systems (230A, 230B; 630A, 630B), respectively covering an upper face and a lower face of the amplification element, the upper, respectively lower, face of the amplification element consisting of the upper faces, respectively lower faces, of the amplifying plate and of the two end bars, where - each temperature control system (230A, 230B; 630A, 630B) comprises a cooling element (231A; 231B; 431 1 ; 431 2 ; 431 3 ; 431 4 ; 431 5 ; 531A), covering a centre region of the upper, respectively lower, face of the amplification element, characterised in that - each temperature control system further comprises at least one heating element (232A; 232B; 432 1 ; 432 2 ; 432 3 ; 432 4 ; 432 5 ; 532B), covering peripheral regions of the upper, respectively lower, face of the amplification element; and - the temperature control systems (230A; 230B; 630A; 630B) are substantially symmetrical to each other, according to an orthogonal symmetry with respect to a plane (P), said plane (P) being a plane parallel to the upper and lower faces of the amplifying plate (213; 313) and passing through said plate, and each temperature control system having a recovery rate higher than 90% with the symmetrical part of the other temperature control system. <EOS>