The purpose of the present invention is to provide a novel indazole compound which is capable of inhibiting HSP90 and has a cytostatic effect. Another purpose of the present invention is to provide a drug useful for preventing and/or treating, on the basis of an HSP90 inhibitory effect, a disease in which HSP90 participates, in particular, cancer. A compound represented by general formula (I) or a salt thereof [in formula (I), X, Y1 to Y4, A, B and R1 to R8 are each as defined in claims of the present application].
