A mounting substrate includes: a substrate; a first terminal, a fifth terminal, and a sixth terminal which are disposed in a first region; a second terminal disposed in a second region; a third terminal and a seventh terminal which are disposed in a third region; and a fourth terminal disposed in a fourth region. The mounting substrate includes: a first connecting line which electrically connects the fifth terminal and the second terminal; a second connecting line which electrically connects the sixth terminal and the third terminal; and a third connecting line which electrically connects the seventh terminal and the fourth terminal.