Ferrite sintered magnet

A ferrite sintered magnet, comprising:

• a magnetoplumbite type ferrite crystal grains;
• and
• a two-grain boundary interposed between the ferrite crystal grains,
• the ferrite crystal grains contain Ca, the metal element R, Fe, and the metal element M,
• wherein the metal element R is selected from the group consisting of Bi and rare-earth elements,
• wherein the metal element M is selected from the group consisting of Zn, Cu, Mn, Al, Co, Ni, and Cr,
• wherein a metal composition of the ferrite sintered magnet satisfies the following Formula (5):
• CaaA2bRcFedMe (5);
• wherein, in the Formula (5), A2 is at least one selected from the group consisting of Sr, Ba, and Pb;
• a is 0.15 or more and 0.7 or less, b is 0 or more and 0.45 or less, c is 0.3 or more and 0.85 or less, d is more than 9.35 and less than 11.90, e is 0.1 or more and 0.5 or less, and the sum of a, b, and c is 1, and
• the two-grain boundary contains Ca and La, and a Ca/La atomic ratio at the two-grain boundary is 0.3 to 3.0.