Formula (I) [wherein W represents CR3 (wherein R3 represents a hydrogen atom or the like), R4 represents a hydrogen atom or the like, R5 represents a hydrogen atom or the like, and R9 represents a substituted imidazolyl. R12 and R13 are the same or different and each represents a hydrogen atom or the like, R22 and R23 are the same or different and each represents a hydrogen atom or the like, R24 represents a hydrogen atom or the like, and Y is C-R25 (formula In which R25 represents a hydrogen atom or the like) or a pharmaceutically acceptable salt thereof, and an FGFR inhibitor containing the same as an active ingredient To do.式(I)[式中、Wは、CR3(式中、R3は、水素原子等を表す)等を表し、R4は水素原子等を表し、R5は水素原子等を表し、R9は置換イミダゾリルを表し、R12およびR13は、同一または異なって水素原子等を表し、R22およびR23は、同一または異なって、水素原子等を表し、R24は、水素原子等を表し、Yは、C-R25(式中、R25は、水素原子等を表す)等を表す]で表される含窒素芳香族複素環誘導体またはその薬学的に許容される塩、およびそれを有効成分として含有するFGFR阻害剤等を提供する。
