A method for manufacturing a flexible circuit board with resistor which is buried in the board includes steps of providing a composite board, the composite board comprising a substrate, and a physical development core layer formed on the substrate. A silver halide emulsion layer is formed on the physical development core layer and the silver halide emulsion layer is exposed. A developing solution is applied to the halide emulsion layer and washed to form a silver layer on the substrate. A conductive layer is formed on the silver layer and the conductive layer is etched, forming at least one opening. Such opening exposes a portion of the silver layer which contains a buried resistor. Different processes and materials applied in the above procedure serve to increase or decrease the resistance of the resistor as desired.