To provide a laminated sheet with excellent solder heat-resistance having a thin insulation layer which has a low thermal expansion coefficient, high strength, and excellent laser processability, and to provide a prepreg suitable for obtaining the laminated sheet.

The prepreg is obtained by impregnating a thermosetting resin in a polybenzazole fiber nonwoven fabric. The polybenzazole fiber nonwoven fabric is produced by a wet-papermaking method using a polybenzazole fabric, of which 25-100 mass% is partially flattened or wholly flattened in advance. The thickness of the nonwoven fabric is ≤50 μm. One or several pieces of the prepreg are pasted together to obtain a laminated sheet, which will be used as a printed wiring board.