A grasping treatment unit configured to grasp and treat a living tissue, the grasping treatment unit comprising: a first jaw which extends from a proximal portion toward a distal portion, and which has an outer surface exposed to an outside; a second jaw which extends from a proximal portion toward a distal portion, and which is openable and closable relative to the first jaw; a heating portion including a heating wire, the heating wire being disposed in a range from the proximal portion to the distal portion in the first jaw, continuing without branching from a first extending end which is one end to a second extending end which is the other end in an extending direction, and being configured to generate heat over an entire length from the first extending end to the second extending end when an electric current flows therethrough; and a blade which includes a treatment surface facing the second jaw on the outer surface of the first jaw, and in which a protruding portion, protruding toward the second jaw as compared to other parts of the treatment surface, and an inclined surface (57A, 57B) are formed in at least the distal portion on the treatment surface, the blade being configured to cut open the living tissue by the heat transmitted from the heating wire to the treatment surface, characterized in that the heating wire includes a first heating region (63, 71) provided in the distal portion of the first jaw, and a second heating region (65, 72, 73) provided on the proximal portion side with respect to the first heating region (63, 71) in the first jaw, the electric current flows through the first heating region (63, 71) and the second heating region (65, 72, 73) between the first extending end and the second extending end in the heating wire without shunt current, and the heating portion is higher in calorific value per unit area (ΔS) in the first heating region (63, 71) than in the second heating region (65, 72, 73) in a state where the electric current flows between the first extending end and the second extending end, such that an amount of heat transfer from the heating portion to the treatment surface is greater in the distal portion of the first jaw than in the proximal portion of the first jaw. a first jaw which extends from a proximal portion toward a distal portion, and which has an outer surface exposed to an outside; a second jaw which extends from a proximal portion toward a distal portion, and which is openable and closable relative to the first jaw; a heating portion including a heating wire, the heating wire being disposed in a range from the proximal portion to the distal portion in the first jaw, continuing without branching from a first extending end which is one end to a second extending end which is the other end in an extending direction, and being configured to generate heat over an entire length from the first extending end to the second extending end when an electric current flows therethrough; and a blade which includes a treatment surface facing the second jaw on the outer surface of the first jaw, and in which a protruding portion, protruding toward the second jaw as compared to other parts of the treatment surface, and an inclined surface (57A, 57B) are formed in at least the distal portion on the treatment surface, the blade being configured to cut open the living tissue by the heat transmitted from the heating wire to the treatment surface, characterized in that the heating wire includes a first heating region (63, 71) provided in the distal portion of the first jaw, and a second heating region (65, 72, 73) provided on the proximal portion side with respect to the first heating region (63, 71) in the first jaw, the electric current flows through the first heating region (63, 71) and the second heating region (65, 72, 73) between the first extending end and the second extending end in the heating wire without shunt current, and the heating portion is higher in calorific value per unit area (ΔS) in the first heating region (63, 71) than in the second heating region (65, 72, 73) in a state where the electric current flows between the first extending end and the second extending end, such that an amount of heat transfer from the heating portion to the treatment surface is greater in the distal portion of the first jaw than in the proximal portion of the first jaw.