TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Complex: In the metal complex, the metal atom or metal ion is a transition metal atom or its ion, from between period 4 and period 6 of the Periodic Table. Preferred Condition: In the modified compound, the treatment temperature for heat treatment is in the range of 200-1200 degrees C.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: In the aromatic compound, the number n of nitrogen atoms composing each the structure and the mean distance r ( Angstrom ) from the center of the structure to each nitrogen atom satisfies the condition represented by the following formula (A): 0 not less than r/n less than or equal to 0.7 (A). The number n of nitrogen atoms composing each the structure is from 4 to 6. The r/n is from 0.2 to 0.6. The ratio of the total mass of nitrogen atoms with respect to the total mass of carbon atoms in the aromatic compound is greater than 0 and no greater than 1.1. The structure is a structure of formula (1).m=1 or greater;Q1a, Q1b and Q1c=optionally substituted nitrogen-containing aromatic heterocyclic rings and each may be the same or different, and when 2 or more Q1b groups exist, each may be the same or different, however, at least one group from Q1a, Q1b and Q1c is a 6-membered nitrogen-containing heterocyclic ring; andZ1a and Z1b=direct bonds or linking groups and each may be the same or different, and when 2 or more Z1b groups exist, each may be the same or different, where Q1a and Q1b, and Q1b and Q1c, each form together a polycyclic aromatic heterocyclic ring, when m is an integer of 2 or greater, the two Q1b groups may form together a polycyclic aromatic heterocyclic ring, and Q1a and Q1c may be bonded together via a direct bond or linking group to form together a polycyclic aromatic heterocyclic ring.The structure represented by general formula (1) above is a structure represented by formula (2) or formula (3).Q2a, Q2b, Q2c, and Q2d=optionally substituted nitrogen-containing aromatic heterocyclic rings and each may be the same or different, however, at least one group from Q2a, Q2b, Q2c, and Q2d is a 6-membered nitrogen-containing heterocyclic ring; andZ2a, Z2b, and Z2c=direct bonds or linking groups and each may be the same or different, where Q2a and Q2b, Q2b and Q2c, and Q2c and Q2d may each form together a polycyclic aromatic heterocyclic ring, and Q2a and Q2d may be bonded together via a direct bond or linking group, or may form together a polycyclic aromatic heterocyclic ring.Q3a, Q3b, Q3c, Q3d, Q3e, and Q3f=optionally substituted nitrogen-containing aromatic heterocyclic rings and each may be the same or different, however, at least one group from Q3a, Q3b, Q3c, Q3d, Q3e, and Q3f is a 6-membered nitrogen-containing heterocyclic ring; andZ3a, Z3b, Z3c, Z3d, and Z3e=direct bonds or linking groups and each may be the same or different, where Q3a and Q3b, Q3b and Q3c, Q3c and Q3d, Q3d and Q3e, and Q3e and Q3f may each form together a polycyclic aromatic heterocyclic ring, and Q3a and Q3f may be bonded together via a direct bond or linking group, or may form together a polycyclic aromatic heterocyclic ring.The nitrogen-containing aromatic heterocyclic ring is a ring selected from pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, 1,3,5-triazine ring, 1,2,4-triazine ring, 1,2,4,5-tetrazine ring, 1H-pyrrole ring, 2H-pyrrole ring, 3H-pyrrole ring, imidazole ring, pyrazole ring, 1,2,3-triazole ring, 1,2,4-triazole ring, oxazole ring, isooxazole ring, thiazole ring, isothiazole ring, 1,3,4-oxadiazole ring, 1,2,5-oxadiazole ring, 1,3,4-thiadiazole ring, 1,2,5-thiadiazole ring, and polycyclic aromatic heterocyclic ring that contain these rings. The two nitrogen-containing aromatic heterocyclic rings bonded together via a direct bond or linking group in Q1a and Q1b, Q1b and Q1c, Q2a and Q2b, Q2b and Q2c, Q2c and Q2d, Q3a and Q3b, Q3b and Q3c, Q3c and Q3d, Q3d and Q3e, or Q3e and Q3f are represented by any one of aromatic heterocyclic compound comprising formulae (4-a) to (6-d).X=C(R alpha )-, -N(R beta )-, =N-, -O-, -S- or -Se-, and each may be the same or different;Y=-NH- or =N- and each may be the same or different; andR4b, R4c, R5b, R5c, R5d, R6b, R6c, R6d, R alpha and R beta =hydrogen or a substituent and each may be the same or different, and adjacent substituents may bond together to form a ring.The two nitrogen-containing aromatic heterocyclic rings bonded together via a direct bond or linking group in Q1a and Q1b, Q1b and Q1c, Q2a and Q2b, Q2b and Q2c, Q2c and Q2d, Q3a and Q3b, Q3b and Q3c, Q3c and Q3d, Q3d and Q3e, or Q3e and Q3f are represented by nitrogen-containing aromatic heterocyclic compound comprising formulae (7-a) to (10-e).R7a-R10e=hydrogen or a substituent and each may be the same or different, and adjacent substituents may bond together to form a ring.    TECHNOLOGY FOCUS - POLYMERS - Preferred Cell: In the polymer electrolyte fuel cell, a polymer electrolyte membrane of the polymer electrolyte fuel cell is the one having proton conductivity. Polymer electrolyte membrane of the polymer electrolyte fuel cell is the one having anion conductivity. EXAMPLE - No suitable example given.