In order to use less cerium oxide and achieve higher durability and polishing speeds, these abrasive particles used in an abrasive have: a shell layer (3) which is the outermost shell layer of the abrasive particles and is formed with cerium oxide as the main component; and a middle layer (2) which contains cerium oxide and an oxide of at least one element selected from Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, In, Sn, Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Bi, Th, and the alkali earth metals, and which is formed closer to the center of the abrasive particles than the shell layer (3).