An apparatus (1) for air purification and microbiological safety indoors, particularly for offices, public environment, industrial environments or similar, comprising: a internally hollow base structure (2) having at least one opening the inlet (6) for the air to be treated coming from a substantially closed environment and at least one outlet opening (7) for the treated air, inside said structure (2) in which is provided: - the moving means for moving air from said inlet opening (6) to said outlet opening (7), - means of ozonation (12) for ozonized air, convenient, in a first purification stage, to transform oxygen molecular air from said ozone environment and - means catalyst (13) suitable, in a second purification stage following said first phase, to transform ozone air from said environment cer rado molecular oxygen, wherein said apparatus further comprises means suitable sensors for detecting the ozone concentration of ozone in the closed environment and - a processing unit and control (17) operatively associated with said moving means (8), said means of ozonation (12), said means catalyst (13) and said sensor means ozone, characterized in that said apparatus ( 1) addition means of sensors suitable for the detection of bacterial load in the air and / or adjacent surfaces bacteria consists, wherein said processing unit and control (17) is provided for real-time control of the production of ozone by said means of ozonation (12), depending on the amount of ozone and the bacterial load in the air or on surfaces, as has been detected respectively by said means ozone sensors and said means of sensors bacteria and wherein said processing unit and control (17) is provided to set the length of said first purification stage and, at the end of it, to start the second phase of pu rification by the off ozonation said means (12), and by firing said means catalyst (13) and activating said moving means (8) during said second stage of purification.Un aparato (1) para la purific
