Inspectors of Mines were, until 1920, appointed by the Home Office. An inspector of mines was first appointed in 1843 under an Act of 1842. This Act prohibited payment by truck and the employment of women and girls and regulated the employment of boys in mines and collieries. The inspector had no powers to inspect the construction or safety of mines until the passage of the Coal Mines Inspection Act 1850. In that year four inspectors of coal mines were appointed. A further Act of 1855 laid down general rules for collieries and provided for special rules for individual collieries to be drawn up and approved by the Home Secretary and enforced by legal penalties for infringement. The duties of inspectors were then extended by further statutes to cover ironstone mines (Mines Act 1860), metaliferous mines (1872), stratified ironstone mines (1881), and slate mines (1882). Following the Quaries Act 1894 which referred to the Factory and Workshop Acts 1878 to 1891, mines inspectors were given responsibility for all quarries, whereas previously factory inspectors had been responsible for those using steam power. The duties of the mines inspectors came to comprise inspection both of mines and conditions of work.
The Act of 1850 required colliery owners to provide accurate maps of mines for inspection, and that of 1872 obliged owners to deposit plans of abandoned mines with the Home Secretary. In 1840 a keeper of mining records had been appointed to the staff of the Museum of Economic Geology, and the voluntary deposit of mining plans was encouraged. In 1883 the Mining Record Office was absorbed into the Home Office.
Until 1908 each inspector of mines was in charge of a district of the country and was assisted by local staff. Co-ordination was exercised directly by the Home Secretary at quarterly meetings of inspectors and through supervision by the Domestic Department and, after 1896, the Industrial Department. In 1908 a reorganisation led to the appointment of a chief inspector of mines, heading a new Mines Department of the Home Office. At the same time an electrical inspector of mines was appointed, and grades of sub-inspectors and of inspectors of colliery horses were introduced by 1914. The chief inspector also assumed responsibility for the staff associated with the Mining Record Office in the Home Office. The inspector's districts were re-organised in 1910. A clerk for mineral statistics was appointed, responsible for the preparation of mining statistics and the collection of mine plans. After 1911 this post was combined with that of Secretary to the central Mining Qualification Board, which replaced earlier separate district boards.
In December 1920 the Mines Inspectorate, the Mining Record Office and the Board for Mining Examinations were absorbed within the new Mines Department who thus took over responsibility for ensuring that basic statutory regulations were being met.
In 1942 the Inspectorate was transferred from the Mines Department to the Ministry of Fuel and Power. The Inspectorate was headed by a chief inspector, under whom were eight divisions based on the coalfields, each of which was headed by a divisional inspector of mines. Each division contained a number of district offices, to which the inspectors were attached. Their duties were to ensure observance of the acts and regulations relating to safety, health and welfare in mines and quarries, to inquire into mine disasters and accidents, and to provide information on matters affecting safety, health and training.
After the Ministry was abolished in 1969, the Inspectorate subsequently came under the Ministry of Technology and the Department of Trade and Industry before passing to the Health and Safety Executive.