An electronic component case includes, a lower case including a bottom plate, a side wall having a protruding portion, an engaging projection formed on an outer face of the side wall, and a screw hole formed in the side wall in a region where the protruding portion is provided, and an upper case including a top plate, a side wall in which an engaging hole is formed, and a notched hole formed in the side wall on the top plate side. The protruding portion of the lower case is engaged to the notched hole of the upper case, and the screw hole is exposed in the notched hole. The engaging projection of the lower case is engaged in the engaging hole of the upper case.