The review considers the main methods for modifying plastic as a functional material for the manufacture of biochips as products of the 21st century which make it possible to conduct multiplex assays and to organize so-called laboratories on a chip (lab-on-chip). Physical, chemical, and physical-chemical methods for introducing functional groups to the surface of various polymer materials to impart the desired physical-chemical properties to them (especially to decrease nonspecific sorption on them) and to achieve the effective immobilization of biomolecules and their fragments are considered. The advantages and disadvantages of existing approaches and their applicability to various tasks are discussed.