To provide a medicament which shows more remarkable effect in treatment of activated B-cell like diffuse large B-cell lymphoma (ABC-CLBCL) than the existing Btk inhibitor, and is excellent in safety. The present compound exhibits more remarkable effect in treatment of activated B-cell like diffuse large B-cell lymphoma (ABC-DLBCL) patients, inter alia, ABC-DLBCL patients having CD79B wild-type gene background than the existing Btk inhibitor, and therefore, it can attain the object of the present invention.
