I can't be sure. I've trawled the internet and the closest I can get to it is Ectemnius continuus. Continuus seems to have the same stripe pattern on the abdomen. What worries me is that most photos of that wasp show dark fibular sections of the legs whereas your photo seems to have completely yellow legs. Then I found this:
Thanks Alan! Whow, these photos in flight with a prey are really impressive!
Well I also don't know how relevant are the colours of the legs. I only can list here the species recorded in Spain:
Ectemius borealis, E. cavifrons, E. cephalotes, E. confinis, E. continuus, E. crassicornis, E. dives, E. fossorius, E. guttatus, E. hispanicus, E. hypsae, E. kriechbaumeri, E. lapidarius, E. lituratus, E. massiliensis, E. meridionalis, E. nigritarsus, E. palamosi, E. rubicola and E. sexcinctus.