With the development of technology, the researchers are faced with the challenges of building up systems for generating artificial speech. The aim of speech synthesis is that based on the input information in a form of a text, we generate a signal that is understandable to a man. Of course we strive for artificial speech be as natural as possible. Speech database that is adequate and contains data of good quality is essential for generating a high-quality artificial speech. For the Slovenian language, there are some speech databases, none of which includes voice of a child. Children's speech is specific due to its higher main frequency. It is also more difficult to obtain high-quality voice recordings for the collection due to lower physical and mental characteristics of children and their minority. In the first part of the thesis the procedures for generating artificial speech and peculiarities in the formation of the Slovenian language are described. The second part gives a description of the methods used in the creation of speech database MESSIS, the first speech database of a child speech in the Slovenian language. The collection contains 52-minute long sound recording of 7176 words, of one male speaker.