We investigate the 11-year solar cycle during the Spoerer Minimum (1415--1534 A.D.) by measuring the carbon 14 content in the annual tree rings for the period 1413--1554 A.D. The period of the Spoerer Minimum is assumed to be a prolonged sunspot minimum like the Maunder Minimum (1645--1715 A.D.). However, the 11-year solar cycle, which appears in recent solar variations, was also prominently detected in the carbon 14 record during this period. The amplitude of the 11-year cycle seems to have been modulated only around 1455--1510 A.D.