Rational AG is a German manufacturer and retailer of commercial and industrial kitchen equipment for thermal food preparation.

The company is based in Landsberg am Lech, Germany, and was founded by Siegfried Meister in 1973.

It operates worldwide and has 25 subsidiaries in Europe, Asia, North and South America as well as seven branches in Germany.

In 1976, Meister invented the Rational combi steamer for commercial kitchens and started its production.

[3][4] From 1978 onwards, the company concentrated solely on combi steamers and discontinued all other product lines.

[12][13] Rational AG has 7 national and 25 international subsidiaries in Germany, Europe, Asia, North and South America.