The fused heterocyclic compound represented by formula (1), or an N-oxide thereof, has excellent effectiveness in pest control. In the formula G1 represents a nitrogen atom, etc.; G2 represents a nitrogen atom, etc.; A1 represents a nitrogen atom, etc.; A2 represents a nitrogen atom, etc.; A3 represents a nitrogen atom, etc.; A4 represents a nitrogen atom, etc.; A5 represents a nitrogen atom, etc.; R1 represents a C1-C6 chain hydrocarbon group, etc., optionally having one or more atoms or groups selected from group X; R2, R3 and R4 are the same or different, and represent a C1-C6 chain hydrocarbon group, etc., optionally having one or more atoms or groups selected from group X; R5 and R6 are the same or different, and represent a C1-C6 chain hydrocarbon group, etc., optionally having one or more atoms or groups selected from group X; and n represents 0, 1, 2.