To provide a method and apparatus for efficiently producing a β- diketonate metal complex suitable for chemical vapor phase deposition method in formation of dielectric thin film of a semiconductor device in high purity.

A reactor 10 for obtaining a reaction solution (M10) of β- diketonate metal complex by reacting a metal with a β-diketone, a filtration device 20 for filtering the reaction solution (M0), a solvent-distilling away device 30 for removing a solvent of a filtration solution (M1) to afford crude crystal and preparing recrystallization solution (M2) from the crude crystal by using a solvent, a recrystallization device 40 for recrystallizing the recrystallization solution (M2) to afford purified crystal and preparing a purified crystal solution (M3) from the purified crystal and a vacuum drying device 60 for obtaining a β-diketonate metal complex (M) by drying the purified crystal solution (M3) in vacuum are successively connected through a valve and piping and each device is connected through a valve to an inert gas feed facility 70 and a vacuum discharge means 80 and each treatment is carried out under inert gas atmosphere and the solution is successively transferred between each device by the difference of pressure.