PURPOSE: To increase the yield of pellet mounting process by a method wherein objective pellets only are irradiated with ultraviolet rays as if they are spot- lighted to deteriorate the bonding strength between an UV sheet and the pellets.

CONSTITUTION: An UV sheet 2 is bonded to a cassette ring 1 fixed to a cassette holder 8 while diced pellets 3 are bonded onto the UV sheet 2. When the cassette holder 8 is aligned on X, Y, θ stages, the UV sheet 2 is previously irradiated with ultraviolet rays through the intermediary of an ultraviolet ray fiber 7 to deteriorate the bonding strength between the UV sheet 2 and the pellets 3. Next, a push up rod 4 is lifted to push up the pellets 3 while a suck up nozzle 6 is lowered. Thus, the pellets 3 about to be peeled from the UV sheet 2 are completely peeled therefrom to be sucked up by the suck up nozzle 6 for shifting them to a mounting device. Through these procedures, the yield of pellet mounting process can be increased.