A particulate positive electrode active material for a lithium secondary cell which satisfies high charge and discharge cyclic durability, high safety, high temperature storage properties, a high discharge average voltage, large current discharge properties, a high weight capacity density, a high volume capacity density, etc. in a well-balanced manner is provided. A particulate positive electrode active material for a lithium secondary cell, which is represented by the formula Li_pCo_xM_yO_zF_a (wherein M is at least one element selected from Groups 2 to 8, 13 and 14 of the Periodic Table, 0.9p1.1, 0.980x0.9999, 0.0001y0.02, 1.9z2.1, 0.9x+y1 and 0.0001a0.02), wherein fluorine atoms and element M are unevenly distributed on the particle surface, the atomic ratio of fluorine atoms to cobalt atoms (a/x) is from 0.0001 to 0.02, and in powder X-ray diffraction using CuK-ray, the half value width of the angle of diffraction on (110) plane is from 0.06 to 0.13, and the half value width of the angle of diffraction on (003) plane is from 0.05 to 0.12.