Provision of a TRPA1 activity inhibitor capable of reducing sensory irritation to skin or mucous membrane and an agent for reduction of sensory irritation for skin or mucous membrane. A TRPA1 inhibitor and an agent for reduction of sensory irritation for skin or mucous membrane comprising as an active ingredient a compound represented by the following formula (1) wherein R1 and R3 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2 represents an alkyl group having 1 to 6 carbon atoms, R4 represents a hydrogen atom, a methyl group or an ethyl group, and a double line composed of a dotted line and a solid line represents a single bond or a double bond.
