The objective of the present invention is to provide a highly safe agent that has excellent biofilm formation inhibiting capability and/or formed biofilm removing capability, and a biofilm formation inhibiting method and/or a biofilm removing method using the agent. Provided are a biofilm formation inhibiting agent and/or removing agent containing, as an active ingredient, at least one selected from anthranilic acid or an anthranilic acid derivative represented by general formula (1), or a salt of those, and a biofilm formation inhibiting method and/or removing method using the biofilm formation inhibiting agent and/or removing agent. (In the formula, each of R1-R4 independently represents the following. R1: C(=O)OH (carboxyl group), C(=O)NH2, C(=O)OCnH2n+1 (alkyl ester: n=1-4). R2, R3: halogen atom, nitro group, hydrogen atom. R4: hydrogen atom, CH3C(=O) (acetyl group), CH3C(=O)CH2C(=O) (acetoacetyl group).)
