NOVELTY - A catalyst, obtained by calcining a hydrazone metal complex in which at least one catalytic metal species is coordinated to a hydrazone compound (I) selected from 4-(1-(pyridin-2-yl-hydrazono)-ethyl)-benzene-1,3-diol, 4-(1-(pyridin-3-yl-hydrazono)-ethyl)-benzene-1,3-diol or 4-(1-(pyridin-4-yl-hydrazono)-ethyl)-benzene-1,3-diol.    USE - As a catalyst (claimed) useful as an electrode catalyst for a fuel cell, as catalyst for exhaust gas purification in automobiles and an ammonium decomposition catalyst. The fuel cells include e.g. alkali fuel cells.    ADVANTAGE - The catalyst enables fine dispersion of a catalytic metal and a polymer compound serving as a starting material for the compound, and these catalyst and polymer compound can be manufactured by simple operations and processes. The catalyst has high dispersivity of a catalytic metal due to high stability of the hydrazone metal complex and is capable of maintaining its dispersed state for a long time. Thus, the catalyst has a high utilization efficiency of a catalytic metal and high catalytic action even with small amounts of the catalytic metal. The formation of the complex inhibits the aggregation of metal species and increases its dispersivity. Moreover, by using the hydrazone compound as a ligand, coordinating it to a catalytic metal species, and forming a complex, the growth of grains occurring in the manufacturing process or utilization of fine particles of catalytic metals is inhibited and a catalyst demonstrating excellent catalytic action with a small amount of catalytic metal can be obtained. Further, by employing the metal complex obtained by using the hydrazone compound and catalytic metal as a starting material compound for an electrode catalyst, it is also possible to obtain a fuel cell with excellent power generation capacity. In addition, the metal complex in which the hydrazone compound and the catalytic metal are coordination bound can be manufactured by the typical conventional method and can be obtained by very simple operations and processes with excellent productivity.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a hydrazone polymer compound comprising at least one structural unit derived from the hydrazone compound (I) as a repeating unit.