Disclosed is a metal thietane compound represented by the following general formula (120), (wherein, in the above general formula (120), M is a member selected from the group consisting of Bi, Sb, Ti, Zr and Ta; X1 and X2 are each independently a sulfur atom or an oxygen atom; R1 is a divalent organic group; the bond between M and T shown by a dotted line and a solid line represents a single or double bond; m is an integer of 0 or 1 or more; n is the number of valence of M; and p is an integer of equal to or more than 1 and equal to or less than n, provided that when r is 1, q is 0 and Y is a monovalent inorganic or organic group; when r is 1 and n-p-q is 2 or more, a plurality of Ys contained are each independently selected from monovalent inorganic or organic groups; when r is 1 and n-p-q is 2 or more, a plurality of Ys may be bonded to each other to form a ring containing M; when r is 2, n-p-q is 1 or 2 and Y is a divalent group; when r is 2 and n-p-q is 2, two Ys may form a ring together with two Ms; and when r is 2 and q is 2, a plurality of Ts contained are each independently selected from inorganic or organic groups).