We present the development of a holographic interferometer based on a dynamic hologram recording with photorefractive crystals of the sillenite family and which is adapted for the observation of MEMS. A compact portable system was already presented in the past and used in various metrology and nondestructive applications on large scattering objects. The great versatility of the instrument, which allows high-resolution measurements, was emphasized. We show the development and achievement of an optical module which can be easily interfaced on the basic instrument, allowing small specular objects’ observation. The results of deformation of electrically actuated MEMS are shown.