Abstract: Apparatus for fine powder dissension, such as dispensing micronised pharmaceutical powder during inhalation therapy, has a container (19) for receiving the fine powder and beads (typically of millimetre size) with a high speed rotor (15) adapted to receive electrostatic charge and through sharp metal arms (17) to establish an electric field while the arm (17) mechanically operates to develop a cloud of fine particles which is discharged through an outlet mesh (21) which retains the beads in the container.