Of autoimmune diseases or allergic disease therapeutic agents

The present invention, an anti-Embigin antibody, comprising an anti-Embigin antibody having a particularly cytotoxic activity or cytotoxic inducing activity, agent for the prophylaxis or treatment of autoimmune diseases or allergic diseases, an agent for the prophylaxis or treatment of diseases in which Th17 cells are involved, to provide a cytotoxic agent to Th17 cells. Furthermore, containing anti Embigin antibodies, agents for detecting Th17 cells, a simple determination method for Th17 cells using the same, a method of selectively and efficiently reach the drug or the like in Th17 cells using anti Embigin antibody , it is provided a drug delivery system into Th17 cells.