To provide a lightweight inner wall panel excellent in workability and causing no trouble due to aging changes by using a shape steel made of a thin steel sheet for the vertical frame materials and vertical core material of a panel frame, and using a wooden material for upper and lower horizontal frames.

The vertical frame materials 21 and vertical core material 27 of a panel frame 11 are formed with a shape steel made of a corrosion-proof this steel sheet, and horizontal frame coupling grooves 23, 25 are provided at the upper and lower end sections. An upper horizontal frame material 31 made of a plywood wooden thin plate is coupled with the upper horizontal frame material coupling groove 23, and a lower horizontal frame material 35 made of a wooden square timber is coupled with the lower horizontal frame material coupling groove 25, they are connected by air pins or the like to form the panel frame 11, and a face material 15 such as a plaster board is fitted at least to one face by air pins or the like to manufacture an inner wall panel 10. The upper horizontal frame material 31 is fixed to a wooden bolster fixed to a ceiling face at a wall forming position in advance, the lower horizontal frame material 35 is fixed to the floor surface by nails or the like respectively, a decorative cloth is stuck, and a ceiling cornice is fitted. The shape steel is used for the vertical frame materials 21 and the vertical core material 27, the wooden material is used for the horizontal frame materials 31, 35, thus the inner wall panel 10 is lightweight and excellent in an execution property, and a trouble due to aging changes does not occur.