Vagus nerve stimulator

A vagus nerve stimulator having at least two electrodes that are configured to be worn on at least one of the left and right ears and are configured to generate electrical stimulation on the vagus nerve in the auricle, the vagus nerve stimulator comprising:

• a body part configured to be located on a side of a wearer's ear;
• a first electrode configured to be inserted into and make contact with the external acoustic meatus of the wearer's ear;
• a second electrode configured to make contact with the cymba concha of the wearer's ear;
• a first electrode fixing part protruding from the body part and having a first electrode at an end thereof;
• and
• a second electrode fixing part protruding from the body part and having a second electrode at an end thereof,
• wherein when a protruding direction of the first electrode fixing part coincides with the x-axis of a three-dimensional coordinate system, an angle between a protruding direction of the second electrode fixing part and the protruding direction of the first electrode fixing part is in a range of 10° to 20° on the xz plane and in a range of 35° to 45° on the xy plane.