A method for dicing a wafer including first and second layers is provided. A front surface of the first layer contacts a backside surface of the second layer. The method includes: forming a sealing film on the second layer; cutting the first layer from a backside surface along with a cutting line to form a notch; removing the sealing film; irradiating a laser beam on the front surface of the second layer along with the cutting line to form a reforming region in the second layer by a multi photon absorption effect; and dividing the wafer along with the cutting line from the reforming region as a starting point of dividing.