A light source unit for plant cultivation includes: a first light emitter emitting a primary light and a converter disposed on a path of the primary light to produce a first light, and a second light emitter emitting a second light, wherein combined light emitted from the first light emitter and the second light emitter produces a basic spectrum including at least three peak wavelengths, with a difference between relative intensities of at least two of the peak wavelengths being less than 20%.