FUNCTIONAL FILM

The invention provides a functional film that has a desired microrelief pattern structure, that sufficiently exerts characteristics of a resin serving as a main component for imparting functions to the functional film, and that has an excellent antifouling property, water-repellency, and oil-repellency. The functional film includes a layer (A) that contains a resin and a layer (B) that contains a compound containing a perfluoropolyether group. The layer (B) has a microrelief pattern structure on a surface remote from the layer (A) . In elemental analysis by X-ray photoelectron spectroscopy with etching by an argon gas cluster ion beam from the layer (B) side, the functional film satisfies the following formula (1): D1 < 2 × X1, wherein X1 is a thickness (nm) of the layer (B); and D1 is a depth (nm) at which fluorine atoms exhibit a concentration of 1 atom% or lower. In carbon 1s spectrum measurement by X-ray photoelectron spectroscopy with etching by an argon gas cluster ion beam from the layer (B) side, the functional film satisfies the following formula (2): D2 < 2 × X1, wherein X1 is the thickness (nm) of the layer (B); and D2 is a depth (nm) at which no peak is detected within a bond energy range of 290 to 300 eV.