From Longman Dictionary of Contemporary Englishinsolein‧sole /ˈɪnsəʊl $ -soʊl/ noun [countable] DCCthe inside part of a shoe, or a piece of cloth, leather etc which is the same shape as your foot that you put inside your shoe
Examples from the Corpus
insole• Board lasting glues the uppers to an insole board before being attached to the midsole, again designed for stability.• The lining is calf leather and there is a comfortable insole of shaped close cell foam.• Williams made his return wearing his infamous red shoes that had specially fitted insoles for his arch.• Further cushioning is provided by the padded insole and tongue.• Polycotton lining with a removable insole.• There's a removable shaped insole with a Cambrelle top to wick moisture away from the foot.• I now remembered that I had put a razor blade under the insole of my shoe, and I removed it.• Slip lasting has uppers sewn together under the insole. 