Abstract: Aspects of the invention relate to a device and method for non-contact inactivation of undesirable and/or harmful microorganisms in products using high-voltage nanosecond pulsed electrical field. In certain embodiments, a product may be packaged into a container which is made from a dielectric material and placed between electrodes to be processed by a pulsed electrical field. In certain embodiments, the electrodes, together with the container, may be placed into a treatment assembly filled with a high dielectric permeability media that allows the formation of a quasi-uniform electrical field inside the product and prevents the electrical breakdown of the dielectric material of the container. The electrodes may be connected to a high voltage generator, which forms nanosecond pulses that allow an electrical field of high intensity to penetrate the dielectric material of container walls and gaps between the electrodes and the container's walls to the product without significant energy losses.