To obtain a good deep drawing property and superficiality by cross- linking a laminate of an extruded sheet consisting of a polyolefin foamable composition and an extruded sheet consisting of polyolefin foamable composition containing a radical scavenger before being subjected to heat-foaming.

A laminate of an extruded sheet A consisting of polyolefin foamable composition and an extruded sheet B consisting of polyolefin foamable composition containing a radical scavenger is manufactured, and the laminate is subjected to cross-linking before being heat-foamed. A first method of manufacturing a laminate, each composition is extruded by an ordinary extruder into a sheet and then laminated by heat-melting, extrusion-laminating method, etc. A second method is such that each A, B compositions are extruded into first and second extruders by coextrusion, and resin capable of heat-melting both of them is introduced simultaneously into a third extruder. In this way, the foam body of the B layer becomes lower than that of the A layer in its cross-linking degree, resulting in being flexible and expansible and having a good deep drawing property and superficiality.