The invention provides electron multiple beam devices (1) for probing or structuring a non-transparent specimen (20) with primary electron beams (14) with an array of electron beam sources (3) to generate multiple primary electron beams (14), an electron sensor (12) with electron sensor segments (12a) to detect electrons of the primary electron beams (14) and at least one anode (7) to direct the primary electron beams (14) towards the electron sensor (12). The electron sensor (12) serves to inspect the primary electron beams (14), calibrate the positions of the primary electron beams (14) and possibly adjust final focus length (13) and currents of the primary electron beams before or after a probing or structuring the upper surface (20a) of a non-transparent specimens (20). Further, methods to inspect primary electron beams (14), to adjust final focus lengths (13) and to calibrate the multiple electron beam device (1) are provided.