The foamed sheet of the present invention is a foamed sheet obtained by crosslinking and foaming a polyvinylidene fluoride-based resin composition comprising a polyvinylidene fluoride-based resin, wherein the polyvinylidene fluoride-based resin comprises a vinylidene fluoride-hexafluoropropylene copolymer, a density of the foamed sheet is not more than 180 kg/cm3, and an average cell diameter of the foamed sheet is not less than 100 μm and not more than 500 μm. According to the present invention, a crosslinked polyvinylidene fluoride-based resin foamed sheet having both good flame retardance and good flexibility and a process for producing the foamed sheet are provided.