To obtain a mixed liquid of a natural fruit juice and vinegar by freezing cut natural fruits to disrupt the natural fruits' tissue followed by thawing and then adding vinegar to infiltrate the vinegar with natural fruits ingredients under a vacuum, and then grinding the thawed fruits with a mixer or the like and squeezing them with a squeezer.

The mixed liquid of a natural fruit juice and vinegar is obtained by the following procedure. Less than 300 g natural fruits are cut and soaked in a less than 3% saline solution based on 1 liter water. The resultant cut fruits are freed of water as thoroughly as possible and then bagged and frozen to disrupt natural fruits' tissue. Thereafter, the resultant bag or the like is thawed and less than 45 cc vinegar is added into the bag or the like, which is put to a vacuum to infiltrate the vinegar with natural fruits ingredients, and then the resultant natural fruits are ground with a mixer or the like and squeezed with a squeezer.