PURPOSE: To provide the bonding method of a conductive case which can be bonded surely and with good efficiency.

CONSTITUTION: A grounding land 8 which comes into continuity with a grounding electrode 3a is formed in advance on a board 2. A through hole 6 is made up to a position corresponding to the grounding land 8 from the surface of a conductive case 1. The whole of the bonding part of the conductive case 1 to the board 2 is coated with a nonconductive adhesive 5 in a state that an electronic component 4 has been mounted on the board 2. The conductive case 1 is bonded to the board 2. In this state, a conductive adhesive 7 is injected into the through hole 6 from the surface of the conductive case 1, and the conductive case 1 is connected electrically to the grounding land 8.