The invention provides a (Li, Na, K)(Nb, Ta, Sb)O3 type piezoelectric/electrostrictive ceramic composition excellent in the electric field-induced strain at the time of high electric field application. The piezoelectric/electrostrictive film of a piezoelectric/electrostrictive actuator is a sintered body of a piezoelectric/electrostrictive ceramic composition. The piezoelectric/electrostrictive ceramic composition comprises a perovskite type oxide comprising as A site elements, Li, Na, and K and as B site elements, Nb and Sb and having a ratio of the total number of atoms of the A site elements to the total number of atoms of the B site elements greater than 1 and not less than 1 mol % and not more than 10 mol % of the number of Sb atoms in the total number of atoms of the B site elements and a Mn compound added to said perovskite type oxide.