Circuit board manufacturing method and ink-jet printer

The invention provides a circuit board manufacturing method and an ink-jet printer. A high-precision anti-corrosion layer is obtained by means of ink jet. The circuit board manufacturing method comprises that an anti-corrosion layer (76) covers the surface of a circuit board slab (70) in the shape of a wiring pattern, the surface of a substrate (72) of the circuit board slab (70) is laminated with a conductive body (74), the exposed conductive body is removed through the etching treatment, and therefore the conductive body is in the shape of the wiring pattern. The shape of the anti-corrosion layer which covers the circuit board slab, i.e., the anti-corrosion pattern is generated as image data, ink droplets are sprayed on the surface of the circuit board slab according to the image data, and the anti-corrosion layer in the shape of the anti-corrosion pattern is formed on the surface of the circuit board slab, and ink is sprayed in a way that the number of ink droplets in the line width direction of the anti-corrosion layer extending in the direction being crossed to a mark (78) on the surface of the conductive body is smaller than the number of ink droplets in the line width direction of the anti-corrosion layer extending along the mark direction.