Aromatic sulfonium salt compound

An aromatic sulfonium salt compound represented by the General Formula (I) below:

• (wherein each of E1 to E4 independently represents a substituent represented by the General Formula (II) below or the General Formula (III) below:
• (wherein each of R1 to R4 independently represents hydroxyl, mercapto, a halogen atom, nitro, cyano, C1-C18 alkyl, C6-C20 aryl, C7-C20 arylalkyl, —OSiR21R22R23 or —OP(═O)R24R25, wherein each of R21 to R25 independently represents C1-C18 alkyl, C6-C20 aryl or C7-C20 arylalkyl, wherein methylene groups in the above-described alkyl and arylalkyl are optionally interrupted by —O—, —CO—, —COO—, —OCO—, —OCOO—, —S—, —SO—, —SO2— or —SO3—, and each hydrogen atom in said alkyl, aryl and arylalkyl is optionally substituted with a halogen atom;
• each of a and b represents an integer of 0 to 5 and each of c and d represents an integer of 0 to 4, with the proviso that in cases where each of a to d represents a number of not less than 2, its plurality of substituents represented by R1 to R4 are optionally the same or different;
• and X represents a direct bond, an oxygen atom, a sulfur atom, CR9R10, NR11 or carbonyl;
• each of R9 to R11 represents a hydrogen atom, C1-C18 alkyl, C6-C20 aryl or C7-C20 arylalkyl);
• each of m, n, r and s independently represents 0 or 1 with the proviso that at least one of m and s is 1;
• each of R5 to R8 independently represents the same group as R1 to R4;
• Anq− represents an anion having the valence of q (q represents 1 or 2);
• and p represents 1 or 2 which is a coefficient to maintain the neutrality of the charge).