The invention offers a broadband light source unit that produces using a simple system a supercontinuum lightwave having a flat spectral form and an optical analyzer using the unit. The broadband light source unit has a light source that outputs a first source lightwave, which is a pulse lightwave having periodic pulses with a constant intensity, a conversion means that receives the first source lightwave, produces a second source lightwave having pulses whose intensities are different from one another, and outputs it, and a nonlinear optical medium section that receives the second source lightwave, produces a supercontinuum lightwave having a wavelength band broadened through a nonlinear optical phenomenon, and outputs it. The optical analyzer has the foregoing broadband light source unit, a light-applying section that applies a supercontinuum lightwave outputted from the broadband light source unit to a light-receiving region of a measurement-undergoing object, and an image pickup section that receives a lightwave generated at the light-receiving region by the application of the supercontinuum lightwave and picks up an image of the measurement-undergoing object.