Abstract: A composition for destroying microorganisms is used for destroying microflora (bacteria, protozoan fungi, etc.) in a sessile state (hereinafter, a biofilm). The composition can find its application in medicine, industry, agriculture and various technical fields for destroying biological films comprised of complex bacterial communities in an extracellular polymeric substance (an exopolymeric matrix), which form on different types of surfaces: biological, industrial, etc. The composition is pre-prepared by dissolving an oxidant and a buffer compound in a solvent. Once the composition has been prepared, it is applied to a biofilm on the surface of an object.