To provide a thin interior board for a vehicle capable of being molded to a desired shape using a general-purpose machine and being excellent in strength and rigidity.

The interior board for the vehicle includes a front side member 2 having a plate-like front side base part 6, a front side peripheral wall part 7 extended from its peripheral edge and a front side reinforcement rib 8 arranged so as to be crossed in vertical and horizontal directions and dividing/forming a plurality of rooms H1 and integrally molded by injection molding; and a back side member 3 having a plate-like back side base part 10, a back side peripheral wall part 11 extended from its peripheral edge and a back side reinforcement rib 12 and integrally molded by injection molding. The front side peripheral wall part 7 and the back side peripheral wall part 11 are abutted and joined to each other, and the front side reinforcement rib 8 and the back side reinforcement rib 12 are abutted and joined to each other. Further, on a joint surface 13 of the front side peripheral wall part 7 and the back side peripheral wall part 11, a ventilation hole 14 is formed, and on a joint surface 13 of the front side reinforcement rib 8 and the back side reinforcement rib 12, a communication hole 15 for communicating the respective rooms H1, H2 with the ventilation hole 14 is formed.