To reduce noise which leaks to the outside in an ultrasonic diagnostic apparatus.An internal AC wiring unit 34 is composed of internal AC wiring which is installed on the input side of a power source circuit, and a shield case 38 which accommodates it. The internal AC wiring includes an inlet, a plurality of connectors, a relay substrate, and a plurality of internal AC cables. The internal AC wiring is protected from radiation noise which is generated in a casing 22 by the shield case 38. Thereby, the noise which leaks to the outside via an external AC cable is reduced.
