Provided are a light source unit (14) for an endoscope and an endoscopy system (10), which clarify the color difference between a first dye and a second dye in an observation image. The light source unit has a white LED light source (30) and a band limiting section (32). The white LED light source has an excitation light source (30a) that emits blue excitation light (LE) and a phosphor layer (30b) that emits yellow fluorescence (LF) upon receipt of the excitation light. As a mixture of the fluorescence (LF) and part of the excitation light (LE), the white LED light source outputs light (LO) having an intensity spectrum continuous across blue, green and red regions. The band limiting section (32) reduces part of the output light (LO) in a wavelength band of not lower than a threshold (» T ). The threshold (» T ) is not less than 650 nm. At the threshold (» T ), the first dye (pyoktanin) has an optical reflectance of not less than a constant value, whereas the second dye (indigocarmine) has an optical reflectance of substantially zero.
