A blower drawing air into the air path and discharging air to the discharge duct, including: a frame forming an outer shell; a fan driven by a motor and having a fan outlet, inside the frame; a duct connection part having a duct connection opening, connected to the discharge duct, outside the frame; and an in-frame blow-out part connecting the duct connection part with the fan outlet, inside the frame. The cross-section shape of the air path changes continuously and smoothly at the in-frame blow-out part and the duct connection part, from the fan outlet to the duct connection opening.