While chemistry itself is a modern science, chemical techology is ancient. It dates back at least to the recovery of copper from ores as early as 3500 BC, if not earlier. Early iron was likely obtained from meteorites as can be deduced from its nickel content. But chemical technology covers a larger area than just metallurgy. Pottery also involves chemistry, but perhaps not so obviously to the ancients.
Glazes are very ancient as is glass.
Glass making was well-known to the Romans. Indigo, obtained from the indigo plant, was known in Egypt in 2000 BC, which means that the modestly complex process of bringing the dye into solution by reduction must have been known as well. By the classical period a fair number of chemical substances were identified and used. A number of chemical recipies from the classical period have survived. During the classical period speculation on the underlying nature of substances became part of chemical knowledge.