A polyamide resin composition which contains (A) a polyamide resin, (B) an alkali metal compound and/or an alkaline earth metal compound, and (C) one or more compounds selected from among (C1)-(C4). (C1) salts of one or more metal elements that are selected from the group consisting of group 3, group 4, group 11, group 13 and group 14 elements of the periodic table (C2) at least one organic thermal stabilizer that is selected from the group consisting of hindered phenol compounds, hindered amine compounds and organic phosphorus compounds (C3) a crystalline thermoplastic resin having a melting point lower than the melting point of the component (A) and/or an amorphous thermoplastic resin having a Vicat softening point lower than the Vicat softening point of the component (A) (C4) an acid The component (B) is contained in an amount of 0.03-20 parts by mass relative to 100 parts by mass of the total of the component (A) and the component (C3). If the component (C1)-(C3) are selected, the 0.001-0.05 part by mass of the component (C1) in terms of metal elements, 0.8-20 parts by mass of the component (C2) and 1-50 parts by mass of the component (C3) are contained, respectively.