Present invention relates to a device magnetically separating a sample. The preferred material for the device is plastic. The device is a cuboid plate, which consists of one or two bottom sides and at least two lateral sides. The bottom side has wells on it to accommodate magnetic elements, and the magnetic element which is suitable to be accommodated into the wells comprising column shape, half-column shape, or half circular column shape magnetic elements. The magnetic element comprises permanent magnet or electromagnet, and the permanent magnet is selected from the group consisting of alnico, samarium cobalt, neodymium iron boron, or magnetic ceramic materials. The magnetic elements can adsorb the magnetic samples in the micro plate.