A device for blowing against individual pieces of a material flow conveyed via a freefall path or a link conveyor using a gaseous or liquid medium, comprising at least one connection opening (9) for the gaseous or liquid medium, as well as multiple blowing nozzles (16), via which the gaseous or liquid medium is blown in a controlled way on predetermined individual pieces of the material flow, as well as valves, preferably solenoid valves, assigned to the blowing nozzles (16), through which the blowing procedure is triggered and stopped, a flow channel being provided between each blowing nozzle (16) and the valve seat (19) of the valve assigned to a blowing nozzle (16), which only causes a single deflection of the gaseous or liquid medium. In order to allow optimum positioning of the valves and keep the pressure loss low, the valve plunger (5) of the valve is situated essentially perpendicularly to the blowing nozzle (16) or encloses an acute angle α with the axis of the blowing nozzle (16).