Japan Vilene Company has been developing nanofiber nonwoven fabrics by using electrospinning method. Electrospinning is a useful and effective method to produce nanofiber nonwoven fabrics with fiber diameter of 1 m or less. The nanofibers obtained by this method are homogeneous long fibers, and the nanofiber nonwoven fabrics have high porosity and sharp pore size distribution. In this report, we describe our development examples using nanofiber technique such as substrate for polymer electrolyte membrane, conductive porous sheet and inorganic fibrous nano powders.