A blasting method of processing a bomb by forming an explosive layer on an outermost surface of the bomb to be processed having a casing in a particular shape and by exploding the explosive layer, wherein the explosive layer comprises a first explosive layer formed around the outermost surface of the casing and a second explosive layer formed as to surround the first explosive layer, an explosive in the second explosive layer has a higher explosion velocity than an explosive in the first explosive layer, and the second and first explosive layers are exploded at a certain time interval by igniting a particular region of the second explosive layer. The method allows low-cost blasting of bombs, by relaxing the impact of the scattering casing fragments.