One of the most important techniques involved in the studies of stem cells or progenitor cells is harvesting and purification of target cells. In this paper, we proposed a new technique to harvest cells targeted under the microscope from cells cultured on a dish, which was coated with thermoresponsive polymers that is soluble in water below〜33℃. Using a device that allowed cooling the bottom of the dish locally beneath target cells, a cell or a small cell colony were detached from surface and harvested within about 30 seconds.