The present invention relates to a method for producing metal nanoparticles and metal sulfide nanoparticles using recombinant microorganisms in which phytochelatin synthase and metallothionein are simultaneously expressed as heavy metal adsorption proteins, and a use of metal nanoparticles or metallic sulfide nanoparticles synthesized by the method. According to the present invention, by providinga method for synthesizing metal in the form of nanoparticles, in which the metal was difficult to synthesize by a conventional biological method, it is possible to synthesize metal nanoparticles in an eco-friendly and economical manner, and it is also possible to synthesize metal sulfide nanoparticles using metal and sulfur, and furthermore, the metal nanoparticles conventionally produced by a chemical or biological method significantly increase in yield by using the production method of the present invention.