An apparatus (10) is described for the administration of pharmaceutical products in the form of an aerosol, comprising means for generating a constant flow (11) of air means of generating a pre-established flow of air (14) means for conveying the air flow (15) to the aerial tracts of a patient, means for containing the pharmaceutical product to be nebulized (12), wherein said apparatus (10) envisages means for generating a pre-established flow of air during all expiration phases of the respiratory cycle, said means for generating a pre-established air flow being pneumatically connected with the means for conveying the air flow (15).
