Process for producing levulinic acid, comprising: (a) subjecting a carbohydrate-based substrate to a treatment step, so as to obtain a reaction mixture comprising levulinic acid, 2,5-(hydroxymethyl)furfural, formic acid, water-insoluble humins and water soluble humins; (b) subjecting the reaction mixture to a filtration step, so as to obtain a solid phase comprising water-insoluble humins and a liquid phase comprising levulinic acid, HMF, formic acid, water-soluble humins; (c) heating the liquid phase obtained by step (b), so as to obtain a liquid-vapor mixture at a temperature from 60°C to 95°C and a pressure from 150 mbara to 350 mbara; (d) subjecting the liquid-vapor mixture obtained by step (c) to fractional distillation, so as to obtain: a water-based head phase, an intermediate phase comprising formic acid, and a tail-end phase comprising levulinic acid, HMF, and water-soluble humins; (e) subjecting the tail-end phase obtained by step (d) to a separation process by a thin film evaporator at a temperature from 150°C to 220°C and a pressure from 100 mbara to 350 mbara, so as to obtain a gaseous phase comprising levulinic acid and HMF, and a liquid phase comprising water-soluble humins; (f) subjecting the gaseous phase comprising levulinic acid and HMF to fractional distillation so as to separate the levulinic acid from HMF; wherein the step (a) of treating is performed on a substrate containing sucrose and comprises the following sub-steps: a first sub-step of acid hydrolysis of the sucrose for obtaining a mixture of glucose and fructose; a second sub-step of separating the fructose from the glucose; a third sub-step of treating the fructose, substantially free from glucose, in aqueous environment at acid pH and at a temperature from 120°C to 180°C, so as to obtain the reaction mixture comprising levulinic acid, 2,5-(hydroxymethyl)furfural, formic acid, water-insoluble humins and water-soluble humins. (a) subjecting a carbohydrate-based substrate to a treatment step, so as to obtain a reaction mixture comprising levulinic acid, 2,5-(hydroxymethyl)furfural, formic acid, water-insoluble humins and water soluble humins; (b) subjecting the reaction mixture to a filtration step, so as to obtain a solid phase comprising water-insoluble humins and a liquid phase comprising levulinic acid, HMF, formic acid, water-soluble humins; (c) heating the liquid phase obtained by step (b), so as to obtain a liquid-vapor mixture at a temperature from 60°C to 95°C and a pressure from 150 mbara to 350 mbara; (d) subjecting the liquid-vapor mixture obtained by step (c) to fractional distillation, so as to obtain: a water-based head phase, an intermediate phase comprising formic acid, and a tail-end phase comprising levulinic acid, HMF, and water-soluble humins; a water-based head phase, an intermediate phase comprising formic acid, and a tail-end phase comprising levulinic acid, HMF, and water-soluble humins; (e) subjecting the tail-end phase obtained by step (d) to a separation process by a thin film evaporator at a temperature from 150°C to 220°C and a pressure from 100 mbara to 350 mbara, so as to obtain a gaseous phase comprising levulinic acid and HMF, and a liquid phase comprising water-soluble humins; (f) subjecting the gaseous phase comprising levulinic acid and HMF to fractional distillation so as to separate the levulinic acid from HMF; wherein the step (a) of treating is performed on a substrate containing sucrose and comprises the following sub-steps: a first sub-step of acid hydrolysis of the sucrose for obtaining a mixture of glucose and fructose; a second sub-step of separating the fructose from the glucose; a third sub-step of treating the fructose, substantially free from glucose, in aqueous environment at acid pH and at a temperature from 120°C to 180°C, so as to obtain the reaction mixture comprising levulinic acid, 2,5-(hydroxymethyl)furfural, formic acid, water-insoluble humins and water-soluble humins. a first sub-step of acid hydrolysis of the sucrose for obtaining a mixture of glucose and fructose; a second sub-step of separating the fructose from the glucose; a third sub-step of treating the fructose, substantially free from glucose, in aqueous environment at acid pH and at a temperature from 120°C to 180°C, so as to obtain the reaction mixture comprising levulinic acid, 2,5-(hydroxymethyl)furfural, formic acid, water-insoluble humins and water-soluble humins.