PROBLEM TO BE SOLVED : To provide anti-LgR5 antibodies and immunoconjugates as well as methods for using the same. SOLUTION : Provided is an immunoconjugate comprising an antibody that is an isolated antibody binding to leucine-rich repetition-containing G-protein coupled receptor 5 (LgR5), and a cytotoxic agent, the antibody binding to a particular epitope of human LgR5 and binding to LgR5 at an affinity of 5 nM or less. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT