To improve design properties and productivity of a curved decorative panel and to make decoration of both surface possible and to decrease aging deformation by bonding a surface decorative material or/and a back face reinforcing material on a curved face prepd. by filling and bonding a resin in a part or the whole of narrow channels provided in the thickness direction of a sheet-like base sheet.

Reinforcing materials 2 each consisting of a kraft paper are bonded on both faces of a sheet-like base sheet 1 consisting of a particle board and narrow channels 3 are provided in a comb-like shape so as to make them reach from the surface side to the position just before the kraft paper on the back face side to form a sheet-like base sheet 1 which can be curved. In addition, an injection channel 4 for injection of a resin is provided in the right angles direction to the narrow channels 3 and then, under a condition where the sheet-like base sheet 1 is curved inward to the surface side provided with the narrow channel 3, an ambient temp.-curable adhesive resin 5 is injected from the injection channel 4 and it is cured to form a curved sheet-like base sheet. Thereafter, surface decorative materials 6 consisting of a melamine decorative sheet are bonded on both faces to prepare a curved decorative panel.