Device to deliver at least a substance with a liquid base, containing one or more active principles at least for cosmetic, pharmaceutical, medical and/or trichological use, said device comprising: - at least a tank containing said substance, - a nebulizing group connected to said tank and configured to nebulize said substance, wherein said nebulizing group comprises an actuator and a delivery element defining between them a chamber fluidically connected to the at least one tank, said delivery element is provided, in its thickness, with delivery apertures with a maximum diameter of 10 micrometers, said actuator is chosen from a group comprising a piezoelectric actuator or an ultrasound actuator, and is configured to make said substance contained in said chamber pass through said delivery apertures, wherein the device comprises a container in which at least said nebulizing group and said tank are contained, said container being provided with at least a wall with a through aperture in which the nebulizing group is positioned and with movement guide; said through aperture being occluded by said delivery element which faces directly toward the outside and the device being also characterized in that it is provided with a cover element attached on said container, placed to cover said delivery element and said through aperture, and mobile on said movement guide to assume at least two positions, namely a first closed position that protects said delivery element, and a second open position which allows to have a free opening for the exit of said nebulized substance; wherein at least one of either said cover element or said container is provided with activation elements connected to a management unit and configured to command the activation of said nebulizing group when said cover element is in said open position. - at least a tank containing said substance, - a nebulizing group connected to said tank and configured to nebulize said substance, wherein said nebulizing group comprises an actuator and a delivery element defining between them a chamber fluidically connected to the at least one tank, said delivery element is provided, in its thickness, with delivery apertures with a maximum diameter of 10 micrometers, said actuator is chosen from a group comprising a piezoelectric actuator or an ultrasound actuator, and is configured to make said substance contained in said chamber pass through said delivery apertures, wherein the device comprises a container in which at least said nebulizing group and said tank are contained, said container being provided with at least a wall with a through aperture in which the nebulizing group is positioned and with movement guide; said through aperture being occluded by said delivery element which faces directly toward the outside and the device being also characterized in that it is provided with a cover element attached on said container, placed to cover said delivery element and said through aperture, and mobile on said movement guide to assume at least two positions, namely a first closed position that protects said delivery element, and a second open position which allows to have a free opening for the exit of said nebulized substance; wherein at least one of either said cover element or said container is provided with activation elements connected to a management unit and configured to command the activation of said nebulizing group when said cover element is in said open position.