To provide a base board for a concrete form panel substantially unchanging in weight and cost from conventional weight and cost, by improving an outward appearance of a concrete wall, by preventing a grating-like line from appearing on a surface of the concrete wall even after separating a form.

This base board A for an FRP concrete form panel is molded by projecting a plurality of cross-sectional rectangular projection strip sash bar parts 2a to 2e and 3 in a vertical-horizontal grating shape on a reverse surface 4 of a square thin plate 1. A padding strip part 6 for gradually increasing the thickness toward a side surface 5 from the reverse surface 4, is integrally molded between the reverse surface 4 of the square thin plate 1 and the total length of the side surface 5 of the respective projection strip sash bar parts 2a to 2e and 3. A recessed groove strip part 7 is molded over the total length of a reverse side corner part of the respective projection strip sash bar parts 2a to 2e and 3 contacting with the padding strip part 6, so as to become the substantially same in weight of a padding strip part 6a and a recessed groove strip part 7a.