There is provided a photobase generator and a photosensitive resin composition containing the photobase generator. The photobase generator includes an ammonium salt represented by general formula (1). In formula (1), R
1
to R
4
independently represent an alkyl group having 1 to 18 carbon atoms or Ar, wherein at least one of R
1
to R
4
represents Ar; Ar represents an aryl group having 6 to 14 carbon atoms (excluding carbon atoms contained in a substituent as mentioned below), wherein some of hydrogen atoms in the aryl group may be independently substituted by an alkyl group having 1 to 18 carbon atoms or the like; Y
+
represents an ammonio group represented by general formula (2) or (3); and E represents a hydrogen atom or a group represented by general formula (5).