The reigning world and European champions were humbled 5-1 by the Netherlands in their Group B opener on Friday.
Del Bosque feels his side's first half in Salvador was positive and he refuses to be dispirited about their situation with matches against Chile and Australia to come.
''Rather than being pessimistic, I always prefer to be positive," he told a news conference.
"I must say our first half yesterday wasn't brilliant, but still we managed to move the ball in the middle of the pitch as we like to, we created chances and we even scored first.
"Everything was all right until we conceded the second goal. From then we tried to respond fast and we ended up all disorganised and that's why we suffered that tough punishment."
A loss to Chile in Rio de Janeiro on Wednesday, combined with the Netherlands getting at least a point against Australia, and Spain's World Cup title defence will be over.
Del Bosque is wary of Chile, who overcame Australia 3-1, and the 'suicidal pressure' they are capable of applying.
''I'm concerned of the peculiarity of Chile's game and not so much about our players' mentality," he said.
"I think they are experienced enough to forget about yesterday and focus on Chile.
"As I always said Chile plays with a suicidal pressure. A dangerous one we'll have to face in order to battle it. We'll see if we are able to do so.
"We have an idea of them. It's true they have similar things to the Netherlands but they also have many others which are exclusive to them.''
