A metal film formation method for forming a metal film on a circuit board by using a printing device (10) which is equipped with a substrate holding unit (32) for holding the circuit board (12) and a discharge head for discharging a particle-dispersed liquid prepared by dispersing metal particles in a solvent, wherein a coating film (70) of the particle-dispersed liquid is formed on the circuit board by discharging the particle-dispersed liquid using the discharge head, and the film is heated from the surface in contact with the circuit board by electromagnetic wave irradiation of an electromagnetic wave absorption material (72) which is contained in at least one of the following: in between the circuit board and the coating film, in the substrate holding unit, in the circuit board, or at the bottom of the coating film. Because evaporation of the solvent and the like progresses from the bottom toward the top of the coating film as a result, fusion of the metal particles is not obstructed, so a dense metal fil
