A tumor treatment method for treating a tumor in a subject, the method includes: a step I of administering a therapeutically effective amount of one or a plurality of antibody-IR 700 molecules to the subject, in which the antibody specifically binds to a cell surface protein of the tumor； a step II of inserting an optical probe into the subject； a step III of applying light having a wavelength in a range from 660 nm to 740 nm from the optical probe, to supply energy of at least 1 J/cm2 to at least a part of the tumor； a step IV of waiting for a time until an immune response is elicited in the tumor； a step V of inserting an energy device into the subject； and a step VI of resecting tissues of the subject including the tumor using the energy device.
