To provide an on-vehicle circuit board housing case which can reduce influence of not only radiation noise but also conduction noise while employing a resin member.

An on-vehicle circuit board housing case 100 accommodates an on-vehicle circuit board 106 on which an electronic component is mounted, and includes: a metal foundation member 102 on which the on-vehicle circuit board is placed; and a resin cover member 104 which is installed on the foundation member while covering the on-vehicle circuit board. The on-vehicle circuit board includes a first region 134 to which a plurality of terminals 117b of an external connector 117 are connected and which is positioned in the vicinity of one end 106a of the on-vehicle circuit board. The foundation member includes: a rectangular bottom surface part 108; a frame body 110 which is installed upright in the periphery of the bottom surface part and forms a cavity 140 between the bottom surface part and the on-vehicle circuit board by being brought into contact with the on-vehicle circuit board; and a wall part 112 which is installed upright from the bottom surface part into the cavity and partitions the first region.