To transfer a DNA into a plant cell in a state close to a plant living body without forming a protoplast by dipping a plant tissue, an organ, a plant body or the like with an intactly remaining cell wall in a DNA vector-containing buffer solution or the like and then applying a DC pulse thereto.

A plant tissue, an organ or a plant body 6 with an intactly remaining cell wall such as a section of a carrot tuberous root, a section of a cabbage leaf, a section of a potato tuberous root or a section of a petunia stem is dipped in a buffer solution 5 containing a DNA or a DNA vector filled in a cuvette 1 composed of a transparent plastic and a DC pulse is then applied to the buffer solution 5 with a means 7 for applying square waves connected to electrodes 3 and 4 to transfer the DNA or DNA vector into the plant cell constituting the plant cell, organ or plant body 6 by electroporation. Thereby, the DNA is transferred into the plant cell in a state close to a plant living body without forming a protoplast.