Melt purification device and melt purification method

In a melt purification device having a conveyance mechanism capable of conveying a rotor to the inside and outside of a melt, the melt is simply purified. A molten metal purification device is provided with: a rotor that stirs a molten metal by rotating within the molten metal and discharges an inert gas into the molten metal; a transport unit configured so as to be able to insert the rotor into the melt by moving the rotor relative to the container; a first image capturing unit that captures a first image until the rotor is inserted into the melt; a first detection unit that detects position information relating to the relative position of the rotating member and the melt on the basis of the first image; a conveyance control unit that inserts the rotor into the melt by controlling the conveyance unit on the basis of the position information; a second image capturing unit that captures a second image including the melt while the melt is being stirred; a second detection unit that detects the stirring state of