Abstract: The device comprises a container (1) with a mouth (4′) to which the end of the conduit through which cement falls into the drum (3) of a concrete mixer truck is coupled, said container being fixed and having a trap door (6) for adapting the back part of said drum (3) so that the dust originating from the fall of the cement remains inside sad container (1). Part of the dust goes out through the conduit (9) to a common collector (10) while the other part is suctioned in through a suctioning head (2) formed by a truncated cone-shaped body, the biggest base thereof being coupled to the mouth (3′) for loading the drum (3) and the smallest base leading to a conduit (13) that ends in the common collector (10). The dust is suctioned in from said collector and passed through a container or hopper (22) with filters with the purpose of cleaning and final reception in a tank or common collector (20).