eIDAS, Ley 6/2020
MINECO
EUR
Yes, electronic signatures are generally legally valid in Spain under eIDAS, Ley 6/2020 and sufficient for most contract types without a form requirement. canusign uses the simple electronic signature (SES); for documents with a statutory written-form or notarial requirement it is not sufficient.
In Spain, you can digitally sign most contracts, including: Commercial contracts, Employment contracts. Exceptions are: Public deeds, Real estate transactions.
The responsible authority in Spain is MINECO. They oversee compliance with legal requirements for electronic signatures.