The present invention provides a polyolefin-based resin foam that achieves both flame retardance and compression flexibility at a high level while satisfying a demand for achieving non-halogen (preferably, including non-phosphorus and non-antimony). The present invention is a non-halogen flame retardant resin foam made by crosslinking and foaming a polyolefin-based resin composition, a polyolefin-based resin foam having a 25% compression hardness in a thickness direction of 8 kPa or less as measured in accordance with JIS K6767, wherein the polyolefin-based resin composition contains a polyolefin-based resin, an organic filler and an inorganic filler, a total amount of compounding the organic filler and the inorganic filler being 100 to 200 parts by mass based on 100 parts by mass of the polyolefin-based resin.