||The present work is mainly characterized as being descriptive-explanatory in relation to the Public Ministry of Guatemala and it has been decided to use a deductive method, starting from general world-wide considerations arriving at the most precise aspect, an institution of the Guatemalan Public Ministry with a view to the future. It begins by taking as its basis the historical antecedents of the institution, so as to have a precedent in the explanation of the content. Following on from this it treats the historical development of the concept of the State of Law in order to establish the bonds that unite this institution with the above-mentioned concept, through which it will be possible to note that the existing nexus between the principles that would govern this institution are no more than segments of a state policy in general. The part related to the Compared Right contributes considerable enriching arguments to solve a number of current problems in Guatemala; every comparison between one subject and another of a comparative legislation, without doubt, contributes novel elements and very diverse aspects that serve to enrich it and to take them in consideration for future improvements. Thus, the perspective of the continental or civil Law has been used for such a study, which recognises and defends a Public prosecutor implicated in the State Power System after, among others, the German and Portuguese Fiscal Ministries studies examples. Additionally, the perspective is also taken from what is known as a system of common law where the weight of accusation falls on the victim or the injured party, or on an institution whose popular legitimisation is obtained through suffrage, where the study referring to the accusation in the English system and the North American system makes an important contribution. The contributions made by the compared system to the present work are important to understand the Public Ministry of Guatemala. Continuing on from this, is a study of the Fiscal Ministry of Spain, which is carried out with the greatest diligence possible, since a large part of the Guatemalan penal system and its judicial history comes from the Spanish tradition. It must be remembered that Guatemala was, until a couple of centuries ago, a colony of the Spanish crown and many of its legal institutions have been key to understand the whole system of Guatemalan Right and, therefore, the figure of the Public Ministry. This, after long years of passivity operating in semi-inquisitive, formal or mixed systems has now turned to a system with a greater accusatory tendency, in which it exerts a fundamental and decisive role that turns round all the procedural support mechanisms, so that all the necessary contributions are taken into consideration. Also the common procedural principles are studied between Guatemala and Spain in relation to the exercise of their functions within the penal process such as the legal principle and the principle of impartiality, where both are compared, as well as the mechanisms ad intra of the institution, so as to neither avoid them nor distort them. And finally, a study is made of the Public Ministry of Guatemala: its past, its present and its future, making proposals to improve it. This study attempts, as a final goal, to consolidate the judicial institutions in Guatemala. There is no shadow of a doubt that these, over the last few years, have been eroded and there is a general distrust of them. For this reason it is important to support the strengthening of our institutions from the academic point of view.