A dyeing machine comprising at least one dyeing module which in turn includes: - a first squeezing device for a textile support entering the dyeing module, said first squeezing device being configured to extract excess liquids from said textile support; - a first treatment tank for the textile support coming from said first squeezing device, said first treatment tank being located downstream of said first squeezing device and being configured to be at least partly filled with a first process fluid; - a central tank, located downstream of the first treatment tank and configured to contain said first process fluid or a second process fluid, to prevent oxidation of the textile support when dyeing with the diffusion/fixing of the dye in the fibre of said dyed textile support, or to operate in air to oxidise said dyed textile support; - a second treatment tank for the textile support, said second treatment tank being located downstream of the central tank and being configured to be at least partly filled with at least the same first process fluid that fills the first treatment tank; and - a second squeezing device for said textile support, located downstream of the second treatment tank and configured to remove excess liquids from said textile support, the dyeing machine further comprising: - a hydraulic system to alternately supply, circulate and adjust the levels of at least the first process fluid and the second process fluid in the two treatment tanks (14, 18) and in the central tank respectively; and - movement means (36, 38) for moving the textile support, the dyeing machine being characterized in that the first treatment tank and the second treatment tank have the same shape and the same dimensional and capacity characteristics, wherein the first treatment tank and the second treatment tank are symmetrical with respect to a plane of symmetry lying in the central tank and arranged perpendicularly with respect to the direction of the forward movement of the textile support, and wherein the movement means (36, 38) for moving the textile support are configured to move forward said textile support alternately in both directions, i.e. either from the first squeezing device to the second squeezing device sequentially through the first treatment tank, the central tank and the second treatment tank, or from the second squeezing device to the first squeezing device sequentially through the second treatment tank, the central tank and the first treatment tank, and wherein the first treatment tank, the central tank and the second treatment tank are enclosed by a hermetically sealed upper covering shell. - a first squeezing device for a textile support entering the dyeing module, said first squeezing device being configured to extract excess liquids from said textile support; - a first treatment tank for the textile support coming from said first squeezing device, said first treatment tank being located downstream of said first squeezing device and being configured to be at least partly filled with a first process fluid; - a central tank, located downstream of the first treatment tank and configured to contain said first process fluid or a second process fluid, to prevent oxidation of the textile support when dyeing with the diffusion/fixing of the dye in the fibre of said dyed textile support, or to operate in air to oxidise said dyed textile support; - a second treatment tank for the textile support, said second treatment tank being located downstream of the central tank and being configured to be at least partly filled with at least the same first process fluid that fills the first treatment tank; and - a second squeezing device for said textile support, located downstream of the second treatment tank and configured to remove excess liquids from said textile support, - a hydraulic system to alternately supply, circulate and adjust the levels of at least the first process fluid and the second process fluid in the two treatment tanks (14, 18) and in the central tank respectively; and - movement means (36, 38) for moving the textile support,