PURPOSE: To obtain a continuous sheetlike flame-retardant polypropylene-based cross-linked foam having excellent moldability, heat resistance, heat insulating properties and cushioning properties.

CONSTITUTION: This continuous sheetlike flame-retardant polypropylene-based cross-linked foam comprises (A) a polypropylene-based resin copolymerized with 2-15wt.% of an α-olefin such as propylene or ethylene, having 125-155°C melting point and 0.5-10g/10 minutes MFR, (B) a polyethylenic resin obtained by copolymerizing ethylene with an α-olefin, having 0-30g/10 minutes MFR, (C) a flame-retardant having 0.915-0.940g/cm3 density and 50-80wt.% halogen content and 150-240°C melting point or softening point. The ratio of the components A/B is 1-9 and that of [the components A+B]/the component C is 2.5-99, the component A and the component B are cross-linked, the degree of cross-linking is 20-70% and the expansion ratio is 2-40 times.