An inorganic filler-containing, polyolefin-based resin expanded bead having an expanded core layer of a first polyolefin-based resin, and a cover layer of a second polyolefin-based resin that covers the expanded core layer, wherein a weight ratio of the cover layer to the expanded core layer is 1:99 to 20:80, the expanded core layer contains an inorganic filler in a weight percentage amount of 5 to 90%, and the cover layer contains no inorganic filler or contains an inorganic filler in a weight percentage amount lower than that in the expanded core layer.