How can I save sweet from ants without refrigerator?

Depending on how big your package of sweets is, you might be able to get a sort of "moat" around it. Put it in a dish of water, but on/in a second containment to keep the water off the sweets themselves. My husband does this with the jar of honey and it works great. I guess ants don't like to swim.

You need to place them in something ants can't get into. A box, jar, or sealed plastic bag should to the trick. Note that as @joe points out in the comments, whatever you use has to seal tightly, and the plastic bags have to be thick.