A method of manufacturing a semiconductor device by which a wafer with devices formed in a plurality of regions demarcated by a plurality of streets formed in a grid pattern in the face-side surface of the wafer is divided along the streets into individual devices, and an adhesive film for die bonding is attached to the back-side surface of each of the devices. The adhesive film is attached to the back-side surface of the wafer divided into individual devices by exposing cut grooves formed along the streets by a dicing-before-grinding method, and thereafter the adhesive film is irradiated with a laser beam along the cut grooves through the cut grooves from the side of a protective tape adhered to the face-side surface of the wafer, so as to fusion-cut the adhesive film along the cut grooves.