NOVELTY - Functional nanofiber mat comprises a first nanofiber layer arranged along the first direction and is formed by electrospinning first nanofibers, and a second nanofiber layer arranged along the second direction and at a certain angle with the first direction by intersecting second nanofibers with the first nanofiber layer. The first nanofibers and second nanofibers are alternately laminated and are formed with uniform thickness. The first nanofibers and second nanofibers are made of different polymer materials.    USE - The mat is useful in fuel cell, actuator and power generation devices.    ADVANTAGE - The mat has uniform thickness, density rigidity, versatility, high efficiency and directivity; controls failure of mechanical properties by generating the pattern through scanning the nanofibers at a specific position; utilizes material which exhibit piezoelectric property; induces cellular responses; and selectively improves growth quality when connected to the different types of tissues.    DETAILED DESCRIPTION - Functional nanofiber mat comprises either: a first nanofiber layer arranged along the first direction and is formed by electrospinning first nanofibers, and a second nanofiber layer arranged along the second direction and at a certain angle with the first direction by intersecting second nanofibers with the first nanofiber layer; or the first nanofiber layer arranged along the first direction and is formed multiple layers scanned in one direction by electrospinning the first nanofibers, and a second nanofiber layer provided with multiple layers and is arranged along the second direction and at certain angle with the first direction by intersecting second nanofibers with the first nanofiber layer; or the first nanofibers of zigzag form which are scanned in one direction at the starting point by the electrospinning process and are repeatedly formed along the opposite direction by perpendicularly moving at a certain distance at the end point, and a comb-shaped nanofiber mat formed with multiple laminated structures which do not intersect with each other. The first nanofibers and second nanofibers are alternately laminated and are formed with uniform thickness. The first nanofibers are laminated spaced apart with a constant distance on the same plane. The first nanofiber layer and the second nanofiber layer having different mechanical strength according to the fiber orientation. The first nanofibers and second nanofibers are made of different polymer materials. The second nanofibers are formed by spinning piezoelectric polymer, temperature-sensitive material or humidity-sensitive materials, thus exhibits piezoelectric functionality, temperature sensitivity or humidity sensitivity. The nanofiber mat has two different mechanical properties and flexibility as it has linear pattern and exhibits mechanical strength after the formation of the linear pattern. The nanofiber mat controls the mechanical properties by adjusting the angle of the comb.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the method of producing the functional nanofiber mat.