The present invention relates to an anti-EMAP II antibody or an antigen-binding fragment thereof, a nucleic acid molecule for coding the same, or a preparation method thereof. Also, the present invention provides a method for using the anti-EMAP II antibody or the antigen-binding fragment thereof in preventing, treating or diagnosing EMAP II-mediated diseases, for example, TNF-α-mediated disease or Alzheimer's disease. Furthermore, the present invention provides a method for using the anti-EMAP II antibody or the antigen-binding fragment thereof in detecting or quantifying an EMAP II antigen. The antibody of the present invention may exhibit a more improved antigen-binding capacity compared to existing anti-EMAP antibodies and may treat the TNF-α-mediated disease more effectively.