A circuit substrate includes protruding terminals and has a structure that ensures an excellent connection with an electronic component, such as an IC. The circuit substrate on which an IC is to be mounted includes terminals that are to be electrically connected to solder bumps located on the IC. The terminals protrude from the mounting surface of a substrate body on which the IC is to be mounted. The sectional area of the top surface of each of the terminals is about 1.2 times the sectional area of each of the terminals on the mounting surface.