We confirmed an increase in false recognition for visual short-term memory of the elderly using a recognition task, which was affected by the test method. Old/new judgments and a forced-choice task were used as the recognition tasks and the hit rate, false alarm rate, and d' for each task were compared across age groups. The results indicated that there were significant differences in the hit rate, false alarm rate and d' across age groups for both recognition tasks. However, in the forced-choice task, where judgments could depend on familiarity, the false alarm rate among the elderly group decreased and differences in d' across age groups became smaller. The elderly could input sight information, but had more difficulty to input the geometric details. We concluded that the false alarm rate for short term visual memory increases in the elderly, but it decreases when recognition judgments can be made based on familiarity.