A plant cultivation method of the present invention includes the steps of: placing a plant under a condition at a pressure of not less than 1.5 atmospheres and not more than 10 atmospheres； and cultivating the plant. A plant cultivation device (1) includes: a cultivation chamber (10)； and a compressor (20) which supplies compressed air into the cultivation chamber. A carry-in opening (30), which is provided on a side wall (16) of the cultivation chamber (10) so that a material is carried in/out to/from the cultivation chamber (10) via the carry-in opening (30), is provided with a cover (31) which has a shape that is hemispherical and protrudes toward an inside of the cultivation chamber (10). The cover (31) closes the carry-in opening (30) by being in contact, via a packing (32), with an inner surface of the side wall (16) surrounding the carry-in opening (30). The cultivation chamber (10) has an internal pressure higher than an atmospheric pressure by causing the compressor (20) to supply compressed air into the cultivation chamber (10) in a state in which the carry-in opening (30) is closed. A plant growth rate is improved by cultivating a plant in a high pressure environment which is different from a natural environment. A plant cultivation device is provided for achieving plant cultivation in a high pressure environment.
