There is provided an activator of peroxisome proliferator-activated receptor α which contains: a compound represented by the following Formula (I); a tautomer or stereoisomer of the compound; or a pharmaceutically acceptable salt or solvate thereof (where, in a case where R1, R2, R3, and R8 do not constitute a ring, in the Formula, R1, R2, R3, R6, R7, and R8 may be the same as or different from each other and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms substituted with 1 to 3 halogen atoms, an alkoxy group having 1 to 8 carbon atoms substituted with 1 to 3 halogen atoms, a hydroxy group, an amino group, a carboxyl group, a mercapto group, an alkylsulfanyl group having 1 to 8 carbon atoms, a nitro group, or a cyano group).