A nickel film with electrical conductivity was successfully synthesized via thermal decomposition. A complex consisting of nickel formate ink and triethylenetetramine was coated onto a glass substrate, which was then calcined under a nitrogen atmosphere. The ink complex then became electrically conductive nickel film and showed a bright surface. As the molar ratio of amine to nickel formate was increased, the volume resistivity of the nickel film was decreased to an almost constant level at ratios higher than 2. The volume resistivity of the nickel film was decreased with an increase in the temperature, which resulted in a lower resistivity of 460 mu omega cm at 230 degrees C, and then it was slightly increased at higher temperatures. The obtained nickel film consisted of particles that were approximately 100-200 nm in diameter, which were connected to one another by a bridge-like structure with many voids.