A semiconductor ceramic and a positive-coefficient characteristic thermistor are provided which have a stable PTC characteristic, a high double point, and a wide operating temperature range. The semiconductor ceramic contains, as a main component, a barium titanate-based composition having a perovskite structure expressed by a general formula AmBO3. Out of 100 mol % of the Ti, an amount in a range of 0.05 mol % or more to 0.3 mol % or less of Ti is replaced with W as a semiconductor forming agent, the ratio m of A sites mainly to B sites is 0.99≦m≦1.002, and an actually-measured sintered density is 70% or more and 90% or less of the theoretical sintered density. In the positive-coefficient characteristic thermistor, a component body is formed of the semiconductor ceramic.