To obtain the subject new compound useful for therapeutic treatment of human bodies or animal bodies, especially treatment of skin tumor and subcutaneous tumor by photodynamic therapy.

This compound is represented by formula I [M is H, a metal, or the like; (k) is the inverse of 1/2 of the valency of M] and at least one of the peripheral carbon atoms in the 1-16 positions of the phthalocyanine nucleus is linked via an oxygen atom to an organic group and the remaining peripheral carbon atoms are unsubstituted or substituted by any combination of atoms or groups, provided that the phthalocyaninde is a compound absorbing electromagnetic radiation at a wavelength from 650 nm to 800 nm or its sulfonated derivative, e.g. hexadeca(phenoxy)dihydro-phthalocyanine. The compound is obtained by reacting, e.g. a compound of formula II [Z is chlorine, or the like; (e) is 0-3; (f) is 1-4; (e+f) is 4] with a compound of the formula R-OH (R is an organic group) and reacting one or more obtained compounds with a metal, or the like, as necessary, in an inert liquid under high temperature.