Polyamide resin composition and molded article obtained by molding same

A method of producing a polyamide resin composition, comprising:

• introducing 1) a polyamide resin (A) and 2) an ammonium salt (B) represented by the chemical formula (R(COO−)2.(NH4+)2), wherein R represents a C4-10 divalent aliphatic group, said polyamide resin composition has a sea-island structure in which a sea phase is constituted of said polyamide resin (A) alone, an island phase is constituted of said ammonium salt (B) alone, and wherein said island phase has an average diameter of 5 nm or more and 100 nm or less, into a twin-screw extruder such that a resulting mixture contains 100 parts by mass of said polyamide resin (A) and 0.1 part by mass or more and 10 parts by mass or less of said ammonium salt (B);
• and melt-kneading said resulting mixture at a shear rate of 150 sec−1 or more and 400 sec−1 or less to obtain said polyamide resin composition.