To provide an insulation sheet usable at a high temperature even when thin, usable also within an oil, yielding a laminate without entailing delamination, and usable as an insulation paper excellent in terms of heat resistance and oil resistance.

The provided insulation sheet excellent in terms of heat resistance, chemical resistance, and oil resistance and capable of forming a thin leafy constitution is an insulation sheet using polyphenylene sulfide (PPS) as a resin material excellent in terms of heat resistance and chemical resistance and constituted as a PPS laminate sheet of a double- or triple-layer structure obtained by laminating a PPS resin layer and a PPS non-woven fabric without using an adhesive. A method for manufacturing an insulation sheet including a step of preparing a PPS non-woven fabric by processing, as a paper-like entity, a PPS fiber based on a wet papermaking method, a step of preparing a PPS resin layer by melt-extrusion-molding a PPS resin, and a step of melting and laminating the PPS non-woven fabric on the PPS resin layer is also provided.