[Problem] To provide an anti-human Notch 4 antibody capable of having a neutralizing activity on human Notch 4 or a Notch 4 binding fragment thereof, and a pharmaceutical composition including the same as an active ingredient. [Solution] The present inventors have obtained a mouse anti-human Notch 4 antibody having a high neutralizing activity on and a high binding affinity to the human Notch 4, and specify a sequence of a complementarity determining region (CDR) of the mouse anti-human Notch 4 antibody. Therefore, a humanized antibody having the CDR sequence of the mouse anti-human Notch 4 antibody in heavy chain and light chain variable regions can be constructed.
