The described instrument is a new reflectometer designed to check the normal specular reflectance of 40000 reflectors necessary for the Laser Megajoule (LMJ). This new reflectometer has a high accuracy over the 400–950\text{\hspace{0.17em} nm} wavelength range and allows the delicate measurement of shaped parts. The measurements are relative and several reference mirrors, which are low loss dielectric mirrors \left[R\left(\lambda \right)>99.9\%\right] , are used for the standardization. The apparatus gives an excellent repeatability ( <0.06\% at 2σ) thanks to its design and automatic focalization imaging system. After a brief review that is related to performance evolution of the spectrophotometers, our facility and its components are described. The methodology of focusing and calibration are explained. The capabilities of our device are illustrated through some measurements realized on flat or shaped samples.