A treatment device includes a first energy output portion that is disposed in one of a pair of holding portions and includes first and second operation regions and a second energy output portion that is disposed in the other holding portion of the pair of holding portions and includes third and fourth operation regions. The first operation region projects toward the second energy output portion more than the second operation region. The third operation region projects toward the first energy output portion more than the fourth operation region. Each of the first and third operation regions includes steps.
