A module substrate includes a plurality of electronic components mounted on at least one surface of a base substrate and a columnar terminal connection substrate connected to the one surface of the base substrate on which a plurality of the electronic components are mounted. The terminal connection substrate includes a plurality of conductor portions, at least one corner of the columnar terminal connection substrate is chamfered with a flat surface and/or curved surface, and the terminal connection substrate is connected at a side surface thereof contacting the chamfered surface, to the one surface of the base substrate.