Provided is a plant cultivation device that improves cultivation efficiency and usability. A plant cultivation device comprises: a rack unit provided with cultivation racks on which cultivation units accommodating plants are stored as culture medium units； and a conveying device which moves along a horizontal movement path defined by a guide rail, and performs transport of the culture medium units and loading/unloading of the culture medium units to/from the cultivation racks. Multiple cultivation racks constitute a cultivation rack row, in which the cultivation racks are arranged at multiple levels in an up-down direction. The rack unit comprises: a cultivation storage constituted of multiple cultivation rack rows； and a loading/unloading station having a stock rack row, in which the holding frames of cultivation units not accommodating plants are stored as empty units. The transport device performs loading/unloading of the holding frames to/from the stock rack row.
