The electronic device has: a housing having an opening; a lid attached to the housing to cover the opening; a first substrate fixed in the housing; and a second substrate that has a first electronic component mounted on a first surface thereof, a first component mounting part on the first surface on which a second electronic component is removably mounted, and a third electronic component mounted on a second surface thereof and is fixed in the housing with the first surface facing the opening and the first component mounting part exposed in the opening.