Under the authority of the defence minister, the Chief of Staff of the Army exercises command over the land branch of the Armed Forces.

The Chief of the Staff of the Army convenes the meetings and coordinates the efforts of the Army Staff (EME), the main support body to the JEME responsible for providing the necessary elements of judgment to base its decisions, translate these into orders and ensure their fulfillment.

[2] The creation of an Army Staff (Estado Mayor Central del Ejército) (EMCE) was planned on the Law of 17 July 1904 by which the Ministry of War was authorized to modify its structure.

[5] The need to recover the Army Staff did not take long to appear and in November 1915 the Council of Ministers approved the draft bill of the Army Staff[6] that was approved by the Cortes Generales and on 26 January 1916 the EMCE was re-created with mere technical functions, because it had no executive functions and was only granted such in times of war.

[7] In 1925, the EMCE was once again suppressed and the functions of the JEME were assumed directly by the Minister of War, and the Directorate-General of Campaign Preparation, which served as the Army Staff, was created.