Cathode structure and ionized metal plasma device including the same

The disclosure invention relates to a cathode structure applied in a plasma apparatus. The cathode structure comprises a curved-surface solid part, a fixing part and a containing part. The containing part is disposed between the curved-surface solid part and the fixing part. The curved-surface solid part includes a top curved surface and a bottom surface. A periphery of the top curved surface completely connects a periphery of the bottom surface. The fixing part is configured to fix the cathode structure on the plasma apparatus. The containing part is configured to receive a cathode filament of the plasma apparatus. The containing part connects the bottom surface of the-surface solid part and the fixing part.