PURPOSE: To spread a firework spherically and prevent the cinders of the shell from dropping onto the ground as it is by a method wherein the shell of the firework is formed so as to have the shape of a cup by mixing saw dust with adhesive agent and is finished so that the shell is dispersed nicely when the shell is launched and dispersed.

CONSTITUTION: A shell, formed so as to have the shape of a cup by congealing saw dust mixed with starch glue, for example, through a press machine and the like, is filled with charge, then, the cups are mated so as to form a sphere and the jointing sections thereof are bonded by a tape or the like to use it as the shell of a skyrockegt. The strength of the shell of the skyrocket can be adjusted freely by changing the kind and amount of an adhesive agent employed for bonding. Further, the thickness of the shell can be changed freely. Accordingly, a firework (skyrocket), dispersed nicely, can be produced by using the congealed saw dust as the shell of the firework while the labor of treatment, such as sweeping after launching and the like, can be reduced.