To obtain a laminated sheet, which does not pollute air and can save resources and is stable and favorable in quality, at low cost.

A mechanochemical reaction is taken place in a mixture of the essential components of a thermosetting resin and a hardener with a medium agitating mill so as to obtain a powdery thermosetting resin composition through grinding, dispersion and mixing or preferably, through the addition of fine powdered additive having the average particle diameter of 0.01-1 ηm, a powdery resin composition. By existing the composition at least on the surface of a sheet-like fibrous base material, a prepreg is manufactured. By applying heat and pressure on one sheet or a plurality of piled up sheets of the prepreg, a laminated sheet is manufactured.