The Inspectorate of Education in Spain was created in 1849. During the second half of the nineteenth century, the supervision of schools was for the first time in the hands of professional officials that used uniform education criteria for all schools. As delegates of the government, these helped to consolidate the school system, which, after the enactment of the Public Education Act of 1857, was gradually but very significantly implemented throughout the nation. The article describes the operation of the first provincial inspectors in Teruel, a rural province in the interior of Spain, which had high rates of illiteracy and serious problems with school attendance, teacher remuneration, and lack of schools, especially for girls. This article describes the work of the provincial inspectors, who, through their association with the Provincial Board of Education, managed to improve all aspects related to the working and living conditions of teachers: state exams, pay, classification for promotion or regulation of promotions, transfers and substitutions. It also studies the inspection visits to schools, and their contribution to both the improvement in school organization and the teaching methodology used by teachers in one-room schools.