There is provided a nitrile compound having an excellent controlling effect on arthropod pests represented by the formula (I): wherein m represents in integer of 0 to 4; n represents an integer of 1 to 4; q represents an integer of 0 to 4; Q represents a C1-C4 fluoroalkyl group; Z represents an optionally substituted C2-C6 alkynyl group or a =N-OR