After the end of the war he went into exile in France, where he was interned in a concentration camp. In 1941, he went to work as a mechanic at an aircraft plant in Tolosa. He worked there for 25 years, before retiring in 1966. He remained active within the exiled Spanish anarchist movement, as a member of the CNT's National Federation of the Railway Industry (FNIF). He sided with the CNT's reformist faction when it split and was a delegate to its subcomittee in London. He also acted on the council of the Ateno Libertario in Toulouse. After the reunification of the CNT, in 1969, he was expelled from the organisation.[3]
Marcos Salas died in Tolosa on 12 December 1988.[3]
Álvarez, Santiago (1989). Los comisarios políticos en el Ejército Popular de la República (in Spanish). Ediciós do Castro.
Engel, Carlos (1999). Historia de las Brigadas Mixtas del Ejército Popular de la República (in Spanish). Madrid: Almena. ISBN84-922644-7-0.
Íñiguez, Miguel (2001). "MARCOS SALAS, Angel". Esbozo de una enciclopedia histórica del anarquismo español (in Spanish). Madrid: Fundación de Estudios Libertarios Anselmo Lorenzo. p.372. ISBN9788486864453. OCLC807322760.
Tagüeña, Manuel (2005). Testimonio de dos guerras (in Spanish). Barcelona: Planeta.