It is the objective and purpose of the present invention to provide a monoclonal antibody having the property of causing apoptosis on myeloid cells. This invention relates to a monoclonal antibody having the property of causing apoptosis on myeloid cells, and fragments thereof, and furthermore relates to a hybridoma producing the monoclonal antibody. Since the monoclonal antibodies of the present invention are useful as antibodies recognizing and identifying antigens causing apoptosis on myeloid cells specifically and besides have the property of causing apoptosis on myeloid cells, they may be used as medicine useful in the field of remedies for myelocytic leukemia utilizing the property.