As a child he became an apprentice in a bakery, and in 1919 he joined the Confederación Nacional del Trabajo (CNT, National Confederation of Labour) while only 13 years old.

[2] In 1932 the Spanish Communist Party made a major change in direction when it abandoned the Comintern slogan "Workers' and Peasants' Government" and adopted "Defense of the Republic".

In February 1936 he was a Popular Front candidate for Seville, as PCE representative, and was elected as Deputy to the Cortes, where he joined the communist minority.

The communists were given three ministries, War, Supplies and Public Order, which were led by Antonio Mije, Pablo Yagüe and Santiago Carrillo, respectively.

From the end of June 1937 Mije again assumed the functions of union secretary on the PCE Central Committee, and was involved in issues of the war economy, mobilization and the production of arms factories.

[4] When the Republican forces were defeated in the Battle of the Ebro (July–November 1938) and General Francisco Franco's troops reached the Mediterranean, Mije stayed in Madrid with Jesús Hernández Tomás, Pedro Checa, Luis Cabo Giorla and Isidoro Diéguez Dueñas while the main Communist leadership center was established in Barcelona.

[8] Mije participated in the last session of the Cortes in Spain, held in the Castillo de San Fernando in Figueres on 1 February 1939, then escaped to France.

[4] Mije managed to steer through the complex internal power struggles in the PCE, which became acute after the secretary-general José Diaz died in March 1942.

His body was flown to Seville, where he was buried in the San Fernando civil cemetery on 11 September 1976, in a ceremony attended by over 3,000 people including several leaders of the Communist Party.