Compounds represented by the Formula (A-1) and the Formula (1) or salt thereof are provided. The compounds represented by the Formula (A-1) and the Formula (1) or salt thereof have a .beta.3 adrenergic receptor agonist activity, and therefore are useful as an agent for the prevention and treatment of diabetes, obesity, hyperlipidemia, depression, biliary stone, a disorder derived from hyperactivity of biliary tract, a disorder derived from hyperactivity of digestive tract, interstitial cystitis, overactive bladder, urinary incontinence or a disorder derived from decreased tear secretion, etc. ##STR00001##