Provided are a laminate, a circuit board, and a liquid crystal polymer (LCP) film comprised therein. The laminate comprises a metal foil and an LCP film. The LCP film in the laminate has a dissipation factor before water absorption (Df′0), a dissipation factor after water absorption (Df′1), and a relative percentage difference between dissipation factors (ΔDf′), which is calculated by the following equation: [mathematical expression included] wherein ΔDf′ may be less than or equal to 16%. By controlling ΔDf′ of the LCP film in the laminate, the insertion loss of a circuit board comprising a laminate during signal transmission in low-, medium-, and/or high-frequency bands is decreased and/or inhibited. In addition, the difference between the insertion losses of signal transmission before and after water absorption is decreased, so the laminate is suitable for high-end or outdoor high-frequency electronic products.