The amounts of the impurity elements Al, Si, Zr, Ca, and Y in this Li-containing transition metal oxide sintered body are kept to the following ranges: 90 ppm or less Al, 100 ppm or less Si, 100 ppm or less Zr, 80 ppm or less Ca, and 20 ppm or less Y. The Li-containing transition metal oxide sintered body maintains a relative density of at least 95%, and a resistivity of less than 2*107 Omegacm. According to the present invention, a Li-containing transition metal oxide thin film that is useful as a positive-electrode thin film for a secondary cell or the like can be formed stably and rapidly without any irregular discharge.