There is provided a plant transplantation device capable of reliably sucking a root of a plant into a hole portion, reliably causing the root of the plant to extend downward from the hole portion without remaining in the hole portion, and improving production efficiency without requiring monitoring or manual operations with a simple configuration. The plant transplantation device includes a suctioning means 110 for sucking a root 103 of a plant 101 and causing the root 103 of the plant 101 to pass through a hole portion 121, the suctioning means 110 has a suctioning tube 111 which can be hermetically attached to a lower portion of the hole portion 121 and a suction pipe 112 which causes a negative pressure in the suctioning tube 111, and a water supplying means 130 for supplying water to the root 103 of the plant 101 is provided in the vicinity of the hole portion 121.