A method for manufacturing a flexible printed circuit board includes preliminarily thermally deforming s substrate through heating, forming a circuit pattern with a conductive paste on the preliminarily thermally deformed substrate, and firing the circuit pattern. A flexible printed circuit board includes a substrate, and a circuit pattern formed by firing a conductive paste on a first surface of the substrate. The substrate is preliminarily thermally deformed and, thus, a shrinkage variation thereof before and after firing the conductive paste is zero. Dimensional stability when firing the circuit pattern printed with the conductive paste can be ensured, deterioration of adhesion between the circuit pattern and the substrate attributable to film deformation upon firing can be prevented, and stable adhesion of the circuit pattern can be maintained even after firing.