Method of manufacturing elongated foam sheet, method of manufacturing composite material and elongated foam sheet

A method of manufacturing an elongated core-material sheet, comprising the step of:

• performing a sheet pasting process in which a large number of core-material sheets are arranged and pasted onto one side of an elongated base material sheet to manufacture the elongated core-material sheet where the large number of core-material sheets are lined up in a longitudinal direction of the elongated base material sheet, wherein, in the sheet pasting process, a removable-type pressure-sensitive adhesive is used to paste the large number of core-material sheets to the elongated base material sheet, in the elongated core-material sheet, the large number of core-material sheets are peelable and transferable from the elongated base material sheet, further performing, before the sheet pasting process, a slice process in which the core-material sheet is created by slicing a foam block and a sheet stretching process in which a curl of the core-material sheet created by the slice process is reduced by passing through a stretching device that heats and stretches the core-material sheet, and, wherein, in the sheet pasting process, the core-material sheet that is reduced in the curl by the sheet stretching process is pasted to the base material sheet, wherein the stretching device comprises a plurality of rollers which stretches the core-material sheet while conveying the core-material sheet, and the plurality of rollers includes a heat roller which heat the core-material sheet.