To provide a foaming resin composition having high tensile impact strength and being suitable for production of a crosslinked foam reduced in elution.

The foaming resin composition includes 100 pts.wt. of an ethylene-α-olefin copolymer (A) and 1-80 pts.wt. of a thermally decomposable foaming agent (B) with a decomposition temperature of 120-240°C. In the ethylene-α-olefin copolymer (A): a density is 890-940 kg/m³; a melt flow rate is 0.1-30 g/10min; a swell ratio is 1.25-1.55; a molecular weight distribution is 4.5-13; flow activation energy is 40-100 kJ/mol; a long chain branching number measured by NMR is 0.29-0.50 per 1,000 carbon atoms; and g* defined by following expression (I), g*=[η]/([η]_GPC×g_SCB*), is 0.76-0.88.