The secondary beam diagnostics at the ACCULINNA-2 fragment separator is implemented event-by-event by the beam particle detector, allowing one to identify the projectile ion with the dE-ToF method and determine the ion’s velocity vector and localization on the target. The detector comprises two ToF stations and a pair of MWPCs. Two identical ToF stations located on the straight section of the ACCULINNA-2 fragment separator form a base of 12.35 m. In each station, light from a thin organic scintillator is detected with four compact PMTs directed symmetrically inside a closed volume. MWPCs are stationary shells designed to work in vacuum at atmospheric pressure of gas CF 4 . Each chamber provides XY coordinates with a pitch of 0.125 cm. This work studies the purpose and scope of application of the beam particles detector and its characteristics, layout, operation logic, as well as techniques of setting and calibration.