A micro plate treating device (10, 30), comprising a micro plate (13, 14, 35-38, 131-135, 141-144, 351-359) having wells (16, 17, 39-42) arranged in a first matrix form, the first matrix form being composed of at least a first and a second partial well matrix, one or more nozzle heads (11, 12, 31-34, 100) each having nozzles capable of sucking and discharging a fluid, the nozzles of each nozzle head being arranged in a second matrix form, wherein the second matrix form corresponds to the first and second partial well matrix, and moving means capable of attaining relative movement between the micro plate (13, 14, 35-38, 131-135, 141-144, 351-359) and the nozzle heads (11, 12, 31-34, 100), wherein tips of all the nozzles arranged in each of the nozzle heads (11, 12, 31-34, 100) are configured to be permitted to be simultaneously inserted into all the wells (16, 17, 39-42) of the first partial well matrix or into all the wells (16, 17, 39-42) of the second partial well matrix of the micro plate (13, 14, 35-38, 131-135, 141-144, 351-359), wherein a well group is defined, the well group being formed of adjacent wells (16, 17, 39-42) of the first and the second partial well matrices, the number of wells (16, 17, 39-42) in a well group being equal to the number of partial well matrices and wherein each individual nozzle of the nozzle head is exclusively dedicated to one well group and is permitted to be inserted into all the wells (16, 17, 39-42) of one well group, and at least one of the row interval or the column interval of the nozzles is set to a natural number multiple of the row interval or the column interval of the corresponding wells (16, 17, 39-42), the natural number being two or more, and at least one of the row number or the column number of all the corresponding nozzles is one divided by the natural number, multiplied by the row number or the column number of the wells (16, 17, 39-42) respectively, and the nozzle heads (11, 12, 31-34, 100) are each comprised of nozzle rows in which the nozzles are arranged in the direction of the well rows and nozzle columns in which the nozzles are arranged in the direction of the well columns, and two or more magnets (61, 65) fitted to be relatively moved along the row direction or the column direction between at least one of gaps between the nozzle rows or the nozzle columns, whereby the magnets (61, 65) can be brought into contact with the nozzles and separated therefrom in such a manner that a magnetic field can be simultaneously applied to the insides of the nozzles and removed therefrom. one or more nozzle heads (11, 12, 31-34, 100) each having nozzles capable of sucking and discharging a fluid, the nozzles of each nozzle head being arranged in a second matrix form, wherein the second matrix form corresponds to the first and second partial well matrix, and moving means capable of attaining relative movement between the micro plate (13, 14, 35-38, 131-135, 141-144, 351-359) and the nozzle heads (11, 12, 31-34, 100), wherein tips of all the nozzles arranged in each of the nozzle heads (11, 12, 31-34, 100) are configured to be permitted to be simultaneously inserted into all the wells (16, 17, 39-42) of the first partial well matrix or into all the wells (16, 17, 39-42) of the second partial well matrix of the micro plate (13, 14, 35-38, 131-135, 141-144, 351-359), wherein a well group is defined, the well group being formed of adjacent wells (16, 17, 39-42) of the first and the second partial well matrices, the number of wells (16, 17, 39-42) in a well group being equal to the number of partial well matrices and wherein each individual nozzle of the nozzle head is exclusively dedicated to one well group and is permitted to be inserted into all the wells (16, 17, 39-42) of one well group, and at least one of the row interval or the column interval of the nozzles is set to a natural number multiple of the row interval or the column interval of the corresponding wells (16, 17, 39-42), the natural number being two or more, and at least one of the row number or the column number of all the corresponding nozzles is one divided by the natural number, multiplied by the row number or the column number of the wells (16, 17, 39-42) respectively, and the nozzle heads (11, 12, 31-34, 100) are each comprised of nozzle rows in which the nozzles are arranged in the direction of the well rows and nozzle columns in which the nozzles are arranged in the direction of the well columns, and two or more magnets (61, 65) fitted to be relatively moved along the row direction or the column direction between at least one of gaps between the nozzle rows or the nozzle columns, whereby the magnets (61, 65) can be brought into contact with the nozzles and separated therefrom in such a manner that a magnetic field can be simultaneously applied to the insides of the nozzles and removed therefrom.