Tricyclic compound and jak inhibitor

Provided is a novel tricyclic compound which has JAK inhibitory activity and is especially useful for prophylaxis, treatment or amelioration of autoimmune diseases, inflammatory diseases and allergic diseases. A novel tricyclic compound which is represented by formula (I), formula (II) or formula (III) (wherein each of A 1 , A 2 and A 3 represents a cyclohexane-1,4-diyl group or the like; each of L 1 , L 2 and L 3 represents a methylene group or the like; each of X 1 and X 3 represents O or NH; each of R 1 and R 3 represents a cyano C 1-6 haloalkyl group or the like; and R 2 represents an aromatic heterocyclic group), a tautomer or a pharmaceutically acceptable salt of the compound, or a solvate of the compound, the tautomer or the pharmaceutically acceptable salt.