Process for dehydration of an ethanol feedstock into ethylene comprising: a) The vaporization of said ethanol feedstock in a mixture with at least a portion of the purified water stream that is recycled according to stage f) in an exchanger owing to a heat exchange with the effluent that is obtained from the last reactor, with said ethanol feedstock in a mixture with at least a portion of said purified water stream that is recycled being introduced into said vaporization stage at a pressure of between 0.1 and 0.4 MPa, b) The compression of said ethanol feedstock in a mixture with at least a portion of the purified water stream that is recycled according to stage f), vaporized, in a compressor, c) The introduction of said ethanol feedstock that is in a mixture with at least a portion of the purified water flow that is recycled according to stage f), vaporized and compressed, at an entrance temperature of between 350 and 500°C and at an entrance pressure of between 0.2 and 1.3 MPa, in at least one adiabatic reactor that contains at least one dehydration catalyst and in which the dehydration reaction takes place, d) The separation of the effluent that is obtained from the last adiabatic reactor of stage c) in an effluent that comprises ethylene at a pressure that is lower than 1 MPa and an effluent that comprises water, e) The purification of at least a portion of the effluent comprising water that is obtained from stage d) and the separation of at least one stream of purified water and at least one unconverted ethanol stream, f) The recycling of at least a portion of the purified water stream that is obtained from stage e), upstream from stage a). a) The vaporization of said ethanol feedstock in a mixture with at least a portion of the purified water stream that is recycled according to stage f) in an exchanger owing to a heat exchange with the effluent that is obtained from the last reactor, with said ethanol feedstock in a mixture with at least a portion of said purified water stream that is recycled being introduced into said vaporization stage at a pressure of between 0.1 and 0.4 MPa, b) The compression of said ethanol feedstock in a mixture with at least a portion of the purified water stream that is recycled according to stage f), vaporized, in a compressor, c) The introduction of said ethanol feedstock that is in a mixture with at least a portion of the purified water flow that is recycled according to stage f), vaporized and compressed, at an entrance temperature of between 350 and 500°C and at an entrance pressure of between 0.2 and 1.3 MPa, in at least one adiabatic reactor that contains at least one dehydration catalyst and in which the dehydration reaction takes place, d) The separation of the effluent that is obtained from the last adiabatic reactor of stage c) in an effluent that comprises ethylene at a pressure that is lower than 1 MPa and an effluent that comprises water, e) The purification of at least a portion of the effluent comprising water that is obtained from stage d) and the separation of at least one stream of purified water and at least one unconverted ethanol stream, f) The recycling of at least a portion of the purified water stream that is obtained from stage e), upstream from stage a).