Abstract: When tableware is washed and rinsed in a dishwasher using a plurality of washing steps, the tableware is washed within 10 minutes using acid ionized water having a pH value of at most 6.0 and a temperature of at least 40.degree. C. in a first washing step, whereby dirt is made to form cohesion and is prevented from being reattached to the tableware, so that a washing load in the following washing steps is reduced. Furthermore, the tableware is washed for at least 15 minutes with alkaline ionized water having a pH value of at least 8.5 and a temperature of at least 55.degree. C. in at least one of the washing steps, whereby the washing effects on fats and oils, protein and starch are improved.