Abstract: In a vector purification device, bacteria containing vectors are cultured in a culture medium in a culture tank, the culture medium is concentrated by filtration with a first TFF film, and the concentrated culture medium is replaced with a buffer solution by filtering a mixture of the culture medium and the buffer solution by the TFF film while supplying the buffer solution from a buffer tank. The bacteria subjected to bacteriolysis by an alkali solution supplied from an alkali tank are passed through a second TFF film to remove undesired substances. Since the TFF films are used in place of a centrifugal separator for concentration or the like, a series of operations can be carried out continuously in a closed system. Further, a crudely purified vector solution is treated with a surfactant to separate vector DNAs from endotoxins as separate layers, and the endotoxins are removed.