<p>Disclosed is a radiation-sensitive resin composition which has excellent sensitivity and can keep an MEEF value at a satisfactory level. Specifically disclosed is a radiation-sensitive resin composition which comprises: a resin (A1) having a repeating unit represented by the formula (1-1) and a repeating unit represented by the formula (1-2); and a radiation-sensitive acid generator agent (B) and which enables to reduce a mask error factor. (1-1) (1-2) wherein R1, R2 and R3 independently represent a linear or branched alkyl group having 1 to 4 carbon atoms; R4 represents a hydrogen atom, a linear or branched alkyl group having 2 to 4 carbon atoms, a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms, or a linear or branched alkoxy group having 1 to 4 carbon atoms; and q represent an integer of 0 to 3.</p>
