Gamow-Teller (GT) transitions are mediated by the στ operator. Owing to its simplicity and also its spin-isospin nature, GT transitions play key roles in the studies of nuclear structure as well as astro-nuclear processes. In violent neutrino-induced reactions at the core-collapse stage of type II supernovae, Gamow-Teller (GT) transitions starting from stable as well as unstable pf-shell nuclei play important roles. We study GT transitions starting from 47Ti in a high-resolution (3He,t) charge-exchange reactions at 0° and at an intermediate incident energy of 140 MeV/nucleon at Research Center for Nuclear Physics (RCNP), Osaka. Individual GT transitions up to high excitations were observed. Assuming the isospin symmetry for the strengths of Tz=±3/2→±1/2 analogous GT transitions, we can deduce the detailed strength distribution starting from mirror unstable nucleus 47Mn.