The present invention relates to a method for manufacturing metal nanoparticles including: preparing a first solution including a metal precursor and a non-polar solvent; preparing a second solution with adding a capping molecule presented by the following Formula 1 into the first solution; and stirring the second solution with applying heat, wherein R1 and R2 are independently —COOH, —NH2 or —CH3 but R1 and R2 cannot be —COOH at the same time, and x and y is independently an integer from 3 to 20 respectively and x+y is 20 to 40.