PURPOSE: To improve the assembly/transfer work performance by storing a die which constitutes a metal mold and a die holder in division, transferring the die and die holder between a warehousing/delivery station and an assembly/ disassembly station by a picking trolley.

CONSTITUTION: A multistoried warehouse 1 is constituted by installing unit storage racks 2a-2j having the storage shelves in plural stages and plural rows, and stacker cranes 3a-3e are arranged between the racks 2a-2j, and warehousing/ delivery stations 4a and 4b are arranged at both ends. Further, contiguously to the warehousing/delivery stations 4a and 4b, assembly/disassembly stations 5a and 5b are arranged. Positioned on the stations 4a, 4b, 5a, and 5b, rails 6a and 6b are laid so as to turn through the above-described stations, and a picking trolley 7 is allowed to travel. The picking trolley 7 is controlled so as to travel in pairs consisting of two units, when at least a die 9 and a die holder 10 are delivered and assembled.