A conveyor apparatus for a particulate material to be conveyed, e.g., a synthetic resin granulate or powder, with a plurality of handling devices (30, 31) for processing the conveyed material, a storage bin (20) for the material to be conveyed, a conveying line (2) provided with a suction probe (1) for withdrawing the material to be conveyed from the storage bin, and a negative pressure source (4) connected to the handling devices via a suction line (7). The handling devices (30, 31) are all connected to a common conveying line (2), and a control member (8) is provided on the suction probe (1) to control the air volume going through the conveying line (2). This control member is controlled by an air pressure sensor (5) disposed on the suction line (7).