A shield casing including a metal shield casing body covering a circuit board to which a electrical cable is connected, the shield casing body including a top portion, side walls and an opened bottom portion, a cable introduction portion formed by partly notching one of the side walls, the electrical cable being introduced into the cable introduction portion in parallel with the top portion, and a contact piece extending perpendicularly from the top portion towards the bottom portion and positioned above the cable introduction portion, the electrical cable being welded on the contact portion by soldering.