The purpose of the present invention is as follows: in an emission region formed by light beams emitted to a plant to be cultivated, to increase light volume and optimize emission conditions using a simple configuration. This plant cultivation device is provided with the following: a first light source unit comprising a first semiconductor laser that emits a first light beam and a first scanning mechanism that scans the first light beam to form a first emission region a second light source unit comprising a second semiconductor laser that emits a second light beam and a second scanning mechanism that scans the second light beam to form a second emission region and a signal processing unit for controlling the first light source unit and the second light source unit. The signal processing unit forms a plurality of emission regions by superimposing the first emission region and the second emission region.