Nonwoven microfibrous materials based on poly(3-hydroxybutyrate) (PHB) were produced by electrospinning. The fiber supramolecular structure was investigated using DSC and EPR. It was shown that the PHB fiber consisted of perfect and less perfect crystallites with an amorphous phase that combined regions of different density. A model of an artificial implant for reconstructive surgery was developed based on a nonwoven fibrous PHB matrix with the required physicomechanical characteristics, high biocompatibility, and the optimal morphology for growth of cell cultures and increased implant regenerative capability.