An in-mold foam molded article has a foam body made from olefin-based resin pre-expanded beads and an insert member having an elongated connecting portion and movement resisting portions provided apart from one another in the elongated connecting portion. The insert member is subjected to insert molding upon in-mold foam molding using the olefin-based resin pre-expanded beads. The foam body has a movement facilitating structure that facilitates relative movement between the insert member and the foam body during shrinkage of the in-mold foam molded article after release from a mold.