A device (100, 200) for monitoring a component of the air, the device comprising a plurality of sensors (140, 240) configured to acquire values of environmental parameters, characterized in that the device (100, 200) further comprises: - a consumable sensor (135, 235) configured to acquire values of concentration of said component, the consumable sensor (135, 235) having a predetermined service life and - a calculator (120, 220) configured to: • in a learning phase, establish a model of the concentration of said component by establishing a correlation between values of concentration of said component acquired by the consumable sensor (135, 235) and values of the environmental parameters acquired by the plurality of sensors (140, 240) and • in a monitoring phase, estimate the concentration of said component using the established model and values of the environmental parameters acquired by the plurality of sensors (140, 240), the monitoring device (100, 200) comprising a chassis (110, 210) in which the calculator (120, 220) is housed and a housing (130, 230) for the consumable sensor (135, 235). the device comprising a plurality of sensors (140, 240) configured to acquire values of environmental parameters, characterized in that the device (100, 200) further comprises: - a consumable sensor (135, 235) configured to acquire values of concentration of said component, the consumable sensor (135, 235) having a predetermined service life and - a calculator (120, 220) configured to: • in a learning phase, establish a model of the concentration of said component by establishing a correlation between values of concentration of said component acquired by the consumable sensor (135, 235) and values of the environmental parameters acquired by the plurality of sensors (140, 240) and • in a monitoring phase, estimate the concentration of said component using the established model and values of the environmental parameters acquired by the plurality of sensors (140, 240), - a consumable sensor (135, 235) configured to acquire values of concentration of said component, the consumable sensor (135, 235) having a predetermined service life and - a calculator (120, 220) configured to: • in a learning phase, establish a model of the concentration of said component by establishing a correlation between values of concentration of said component acquired by the consumable sensor (135, 235) and values of the environmental parameters acquired by the plurality of sensors (140, 240) and • in a monitoring phase, estimate the concentration of said component using the established model and values of the environmental parameters acquired by the plurality of sensors (140, 240), • in a learning phase, establish a model of the concentration of said component by establishing a correlation between values of concentration of said component acquired by the consumable sensor (135, 235) and values of the environmental parameters acquired by the plurality of sensors (140, 240) and • in a monitoring phase, estimate the concentration of said component using the established model and values of the environmental parameters acquired by the plurality of sensors (140, 240), the monitoring device (100, 200) comprising a chassis (110, 210) in which the calculator (120, 220) is housed and a housing (130, 230) for the consumable sensor (135, 235).