To achieve incision and hemostasis well without adversely affecting incising members by arranging the incising members and a laser guide member in side-by-side relationship, incising a tissue by means of the incising members, and directly applying a laser beam to the incised part from the laser guide member to effect hemostasis at the incised part in a treatment apparatus such as an electrosurgical treatment apparatus inserted from a forceps hole in an endoscope.

This electrosurgical treatment apparatus 50 comprises snares 16, 18 and an optical fiber 30 arranged side by side; the snares 16, 18 are used to incise a tissue and a laser beam is directly emitted from the optical fiber 30 toward the incised part for hemostasis at the incised part. Thus, incision and hemostasis can be achieved well at the same time without damaging the snares 16, 18 with laser beams.