The present invention relates to a damper-integrated blower having improved airtightness, which comprises a blower casing a having a suction port and a blower casing b fastened to the casing a from the opposite side; a vane stopper protrusion is formed on bottom surface of the exhaust port, and a vane contact housing part is formed above the exhaust port; damper motor screw fixing parts integrally protrude from the outer upper surface of the vane contact housing part of the blower casing a; a damper motor shaft hole is bored in a damper motor shaft hole protrusion part which is integrally formed on the outer upper side of the vane contact housing part of the blower casing a; a vane rotation shaft protrudes from the inner surface of a damper motor shaft hole protrusion part of the blower casing b facing the damper motor shaft hole protrusion part; an eccentric damper motor shaft of a damper motor is introduced into the damper motor shaft hole so as to connect with the blower casing a; a vane as a single member is connected to the damper motor shaft and the vane rotation shaft so as to open and close the exhaust port; and a gasket is coupled to the four edges of the vane providing a vane module.