The ELI-NP facility (Extreme Light Infrastructure-Nuclear Physics) will deliver an intense and almost monochromatic gamma beam for frontier research in nuclear physics. Peculiar devices and techniques have been developed to measure and monitor the beam parameters during the commissioning and the operational phase. In this work we will present the Compton Spectrometer, designed to reconstruct the γ beam energy spectrum, by measuring the energy and the position of Compton scattered electrons. The energy and the angle of the scattered electron are measured by a High Purity Germanium detector and a double sided silicon strip detector. The associated photon is detected in coincidence with the electron by barium fluoride (BaF2) crystals for trigger purpose. In this work we report the status of the characterization carried out on the detectors composing the spectrometer. •Compton spectrometer, designed to reconstruct the ELI-NP γ beam energy spectrum.•Energy of the scattered e− measured with a High Purity Germanium detector.•Scattered angle determined by a double sided silicon strip detector.•Scattered photon detected in coincidence by BaF2 crystals for trigger purpose.•Tests carried out on the components of the spectrometer are presented.