For its documentary value, the Baška tablet is regarded as the gemstone of the Croatian language, the birth certificate of Croatian culture, a Croatian national treasure. Scientifically, it was discovered in 1851 when Petar Dorčić informed Ivan Kukuljević Sakcinski about it. Since 1934, it has been kept in the palace of the Croatian Academy of Sciences and Arts. Numerous works on the topic of the Baška tablet often also address its language. The more careful and philologically educated researchers immediately noted the co-existence of different Old Church Slavonic and Early Croatian linguistic specificities. However, they do not agree which stratum is its basis. When it comes to the Baška tablet, there is a lot of work to be done even for the younger generations, but we can agree that it is written in the Croatian Old Church Slavonic language. More than 400 letters are inscribed into the Baška tablet, most of which are Glagolitic. The Glagolitic text of the Baška tablet is in between the round and angular variant. Traditional Croatian philology has long noted the letter multiplicities in relation to the smallest linguistic units. One of the greatest graphic specificities is the co-existence of two letters for one grapheme. In this thesis, the Old Church Slavonic and Croatian elements of the text are presented, as well as different perspectives on specific forms by the most prominent Croatian researchers. Along with script analysis, a survey of different letters and their forms is given. Additionally, letter multiplicities in the text are also examined. The script is orthographically analysed, with respect to linear organisation, ligatures, contractions, punctuation, continuous writing, and majuscules.