Salts and crystals of 1-cyclopropylmethyl-4-[2-(3,3,5,5-tetramethylcyclohexyl)phenyl]piperazine have excellent cell adhesion inhibitory action and cell infiltration inhibitory action, and are useful as therapeutic or prophylactic agents for various inflammatory diseases and autoimmune diseases associated with adhesion and infiltration of leukocytes, such as inflammatory bowel disease (particularly ulcerative colitis or Crohn's disease), irritable bowel syndrome, rheumatoid arthritis, psoriasis, multiple sclerosis, asthma and atopic dermatitis.