Abstract: The present invention consists of a differential mobility analyzer (DMA) intended for achieving the electric field conditions necessary so that it has an component opposite to the drag flow. This electric field component opposite to the drag flow causes the main electric field to be not perpendicular to the velocity field of the drag flow but oblique. Under these conditions, it is possible to increase the resolution of the device, thus reducing the threshold of errors in the detection of the type particle injected in the analyzer. This invention is characterized by the arrangement and nature of the electrodes intended for obtaining the oblique electric field. The invention also comprises the use of this analyzer as part of a device which comprises it, giving rise to an assembly combining the efficiency of the analyzer of the state of the art with the high resolution of the analyzer of the invention.