An electronic unit includes a first case made of metal; a second case made of metal; a frame made of synthetic resin arranged inside an assembly of the first case and the second case; a relay member made of metal that is separate from the frame and includes a first connection portion electrically connected to the first case, a second connection portion electrically connected to the second case, and a coupling portion coupling the first connection portion and the second connection portion; a first screw that passes through the first case and the first connection portion from the outside of the first case and is fixed to the frame; and a second screw that passes through the second case and the second connection portion from the outside of the second case and is fixed to the frame.