PURPOSE: To obtain an aseptic seedling by immersing a plant body contaminated during a process of tissue culture into a cell wall digesting enzyme solution, subsequently applying or reducing pressure from the above-mentioned enzyme solution for removal of the contamination and growing the plant body.

CONSTITUTION: For the purpose of removal of various germs from a plant body contaminated during a process of tissue culture, the plant body contaminated with various germs is immersed into a cell wall digesting enzyme solution and pressure is subsequently applied or reduced from the abovementioned enzyme solution. Removal of the contamination in tissue culture is carried out thereby.