A foamable resin composition includes a styrenic thermoplastic elastomer and a dynamically crosslinked thermoplastic elastomer in a total amount of 100 parts by mass. An amount of the dynamically crosslinked thermoplastic elastomer is 10 to 40 parts by mass. The composition further includes high-temperature expandable microcapsules and low-temperature expandable microcapsules in a total amount of 25 to 50 parts by mass relative to 100 parts by mass of the elastomers, and an amount of the low-temperature expandable microcapsules is 17 to 67% by mass relative to the total amount of the two types of microcapsules.