A thermistor sintered body has a thickness in a range of 1 m to 100 m and an area in a range of 1 mm.sup.2 to 10 mm.sup.2, and is composed of a single body of a sintered body having a composition of NiMn.sub.2O.sub.4. This thermistor sintered body can be manufactured by a first step of dropping a raw material liquid RL onto a surface of a substrate rotatably supported, a second step of rotating the substrate with the dropped raw material liquid RL and spreading the raw material liquid RL, a third step of forming a sintered body having the composition of NiMn.sub.2O.sub.4 on the surface of the substrate by heating and holding the raw material liquid RL and the substrate on which the raw material liquid RL has been placed, and a fourth step of separating the sintered body from the substrate.