An evaporating dish is a piece of laboratory glassware used for the evaporation of solutions and supernatant liquids and sometimes to their melting point. Evaporating dishes are used to evaporate excess solvents - most commonly water - to produce a concentrated solution or a solid precipitate of the dissolved substance.
Most are made of porcelain or borosilicate glass. Shallow glass evaporating dishes are commonly termed "watch glasses", since they resemble the front window of a pocket watch. Some used for high-temperature work are of refractory metals, usually of platinum, owing to its non-reactive behaviour and low risk of contamination.
The capacity of evaporators is usually small - in the range 3-10 ml. Larger dishes, up to 100 ml, are different in shape, and are more hemispherical.