In order to avoid an inefficient assembly/disassembly process and wasteful use of materials, it is important to improve the disassembly efficiency of products. In this paper, it is proposed that the choice of shape and labeling of parts may improve disassembly efficiency. In order to verify this assumption, a set of cube puzzles was used for disassembly process experiments. Three experiments were conducted with a total of 56 participants who disassembled seven different types of cube puzzles. The authors compared the average time taken and number of errors committed by participants while disassembling different cubes. The results showed that when participants disassembled a cube puzzle that could be opened via multiple parts, the average number of errors was not different, even though these cube puzzles took more time to disassemble.Thus, puzzle shape had no positive effect on disassembly efficiency. However, when participants disassembled a cube puzzle with only one key clue part that was labeled, it had a positive effect on disassembly efficiency, that is, labeling the first shape to be moved made the disassembly process more efficient.