A three-dimensional cardiomyocyte gel was reconstructed using an extracellular matrix gel formed from Matrigel and collagen I. The autonomous beating of the cardiomyocyte gel was synchronized with contraction of cardiomyocytes in the gel. The gel beating frequency was increased by increasing the concentration of adrenaline in the cardiomyocyte culturing medium. Drug stimulation to modulate the beating frequency could be used for control of a pumping application. A micropump driven by the cardiomyocyte gel was demonstrated. The micropump consisted of two check valves and the cardiomyocyte gel actuator. The volume changes of the channel in the micropump, synchronized with the autonomous gel beating, were seen.