To provide a noble metal nanoparticle dispersed thin film with a shorter range between the noble metal nanoparticles and/or with a smaller diameter of each noble metal nanoparticle by dispersing the noble metal nanoparticles with higher density and its production method.

The noble metal nanoparticle dispersed thin film has the noble metal nanoparticles containing a noble metal and an inorganic material with higher electric specific resistance as compared with that of the noble metal nanoparticles and the in-plane number density of the noble metal nanoparticles is 4.0104/m2 or more to 3.0106/m2 or less. The production method of the noble metal nanoparticle dispersed thin film has the ablation process in which a thin film comprising the noble metal nanoparticles and the inorganic material is formed on a base plate using a pulse laser ablation.