Plant for preparing drugs comprising: a casing defining at least one storage chamber and at least one preparation chamber flanked and communicating with each other by means of at least one passage opening, at least one compartment disposed inside the storage chamber and configured to receive a plurality of base components adapted to contain substances for preparing drugs, such compartment in turn including: ∘ at least one outer sector configured to house a predetermined number of said base components and to rotate around a respective axis, and ∘ at least one inner sector configured to house a predetermined number of said base components and to rotate around a respective axis, the inner sector being at least partly housed in the outer sector, at least one manipulator housed in the preparation chamber and configured for defining a loading condition, wherein the manipulator takes at least one base component from the compartment - through the passage opening - and places it in the preparation chamber, said manipulator being further configured for defining a working condition, wherein the manipulator itself combines the substances contained in the base components transported into the preparation chamber for forming at least one finished product containing a drug, at least one control unit connected to the compartment and to the manipulator, the control unit being configured for: ∘ commanding the compartment to rotate in order to position at least one base component - housed in the outer sector or in the inner sector - at the passage opening, ∘ commanding the loading condition to the manipulator so that the latter takes said base component from the compartment and positions it in the preparation chamber, ∘ commanding the working condition to the manipulator for preparing the finished product. a casing defining at least one storage chamber and at least one preparation chamber flanked and communicating with each other by means of at least one passage opening, at least one compartment disposed inside the storage chamber and configured to receive a plurality of base components adapted to contain substances for preparing drugs, such compartment in turn including: ∘ at least one outer sector configured to house a predetermined number of said base components and to rotate around a respective axis, and ∘ at least one inner sector configured to house a predetermined number of said base components and to rotate around a respective axis, the inner sector being at least partly housed in the outer sector, ∘ at least one outer sector configured to house a predetermined number of said base components and to rotate around a respective axis, and ∘ at least one inner sector configured to house a predetermined number of said base components and to rotate around a respective axis, the inner sector being at least partly housed in the outer sector, at least one manipulator housed in the preparation chamber and configured for defining a loading condition, wherein the manipulator takes at least one base component from the compartment - through the passage opening - and places it in the preparation chamber, said manipulator being further configured for defining a working condition, wherein the manipulator itself combines the substances contained in the base components transported into the preparation chamber for forming at least one finished product containing a drug, at least one control unit connected to the compartment and to the manipulator, the control unit being configured for: ∘ commanding the compartment to rotate in order to position at least one base component - housed in the outer sector or in the inner sector - at the passage opening, ∘ commanding the loading condition to the manipulator so that the latter takes said base component from the compartment and positions it in the preparation chamber, ∘ commanding the working condition to the manipulator for preparing the finished product. ∘ commanding the compartment to rotate in order to position at least one base component - housed in the outer sector or in the inner sector - at the passage opening, ∘ commanding the loading condition to the manipulator so that the latter takes said base component from the compartment and positions it in the preparation chamber, ∘ commanding the working condition to the manipulator for preparing the finished product.