Welding portion inspection device

A welding portion inspection device comprising:

• a device body;
• a probe configured to oscillate an ultrasonic wave and detect a reflected wave of the ultrasonic wave;
• a sound propagation medium attached to a tip of the probe;
• an elastic support mechanism configured to allow the probe and the sound propagation medium to be elastically supported to the device body;
• and
• a guide member formed of a material higher in hardness than a hardness of a metal plate, the guide member including a first part and a plurality of second parts, the guide member being disposed such that the first part of the guide member is positioned on a side of the sound propagation medium and the plurality of second parts of the guide member protrude from the first beyond a tip surface of the sound propagation medium, the plurality of second parts of the guide member being disposed at outer sides of the sound propagation medium,
• wherein the probe is configured to (i) oscillate the ultrasonic wave and emit the ultrasonic wave to a welding portion of the metal plate through the sound propagation medium, and (ii) perform inspection of the welding portion based on the detected reflected wave of the ultrasonic wave in a state where the tip surface of the sound propagation medium faces the welding portion.