The present invention provides a new amide compound and salt thereof that is capable of inhibiting biofilm formation or removing deposited biofilm. The present invention also provides a biofilm formation inhibitor or a biofilm remover containing the amide compound or salt thereof as an active ingredient. An amide compound or salt thereof according to the present invention is denoted by General Formula (1): wherein R 1 is a hydrogen atom or a hydroxyl group, R 2 is a C 5-12 alkyl group, and Q is a substituent denoted by Formula (Q1) or (Q2), wherein n and m are 0 or 1.