A coated solder material consisting of: a solder material and a coating film formed on the surface of the solder material; wherein the solder material is one kind selected from among the group of Bi solder material, Bi-Sn solder material, Pb solder material, Sn solder material, Au solder material, In solder material, or Zn -Sn solder material, and the coating film is including a carbon compound as the main component, and the carbon compound is formed by introducing an organic compound having a carbon number of 8 or less together with a carrier gas into a reaction gas that has been plasmatized under atmospheric pressure, and then after a radicalized organic compound has been formed by radicalizing the organic compound, causing the radicalized organic compound to react with the metal on the surface of the solder material, whereas a hydrocarbon gas that includes an aliphatic compound and/or alicyclic compound having a carbon number of 4 or less or a hydrocarbon solvent that includes at least one kind selected from among the group of an aliphatic compound, alicyclic compound and aromatic compound having a carbon number of no less than 5 and no greater than 8 is used as the organic compound; the thickness of the coating film is 4 nm to 200 nm, and the mass-reduction rate α of the coating film after heating at 150°C to 300°C and melting is 60% or greater, whereas the mass-reduction rate α is a value that is found from Equation: α = (w 1 -w 2)/w 1 x 100, where w 1 is taken to be the mass of the coating film before heating and w 2 is taken to be the mass of the coating film after heating at 150°C to 300°C; the difference between the maximum value and the minimum value of the thickness of the coating film is 10 nm or less, whereas the thickness of the coating film and the maximum value and the minimum value thereof is found by observation using a transmission electron microscope TEM and by measuring the thickness of the coating film at three or more arbitrary positions in the cross section of the coated solder material, and calculating the average value, the maximum value and the minimum value. a solder material and a coating film formed on the surface of the solder material; wherein the solder material is one kind selected from among the group of Bi solder material, Bi-Sn solder material, Pb solder material, Sn solder material, Au solder material, In solder material, or Zn -Sn solder material, and the coating film is including a carbon compound as the main component, and the carbon compound is formed by introducing an organic compound having a carbon number of 8 or less together with a carrier gas into a reaction gas that has been plasmatized under atmospheric pressure, and then after a radicalized organic compound has been formed by radicalizing the organic compound, causing the radicalized organic compound to react with the metal on the surface of the solder material, whereas a hydrocarbon gas that includes an aliphatic compound and/or alicyclic compound having a carbon number of 4 or less or a hydrocarbon solvent that includes at least one kind selected from among the group of an aliphatic compound, alicyclic compound and aromatic compound having a carbon number of no less than 5 and no greater than 8 is used as the organic compound; the thickness of the coating film is 4 nm to 200 nm, and the mass-reduction rate α of the coating film after heating at 150°C to 300°C and melting is 60% or greater, whereas the mass-reduction rate α is a value that is found from Equation: α = (w 1 -w 2)/w 1 x 100, where w 1 is taken to be the mass of the coating film before heating and w 2 is taken to be the mass of the coating film after heating at 150°C to 300°C; the difference between the maximum value and the minimum value of the thickness of the coating film is 10 nm or less, whereas the thickness of the coating film and the maximum value and the minimum value thereof is found by observation using a transmission electron microscope TEM and by measuring the thickness of the coating film at three or more arbitrary positions in the cross section of the coated solder material, and calculating the average value, the maximum value and the minimum value.