The article deals with the problem of the legal definition of cyberspace in the Polish law. In connection with the continuing process of transferring human activities into the virtual sphere, new legal problems continually occur. They result, among others, from the technological progress. Activities in the so called cyberspace also become an essential element of the functioning of the individual, as well as the country and its administration. The process of developing IT culture besides advantages also generates certain dangers. This involves the possibility of cyberspace exploitation for purposes conflicting with the interest of the country and its citizens. An example of such dangers are numerous hacker attacks targeting various types of institutions of essential importance in the functioning of the country and the society. The country should be prepared to fight off such attacks, as well as to fight their consequences. Therefore in the Polish law changes have been introduced within the acts referring to emergency situations. The change, among others, involves the introduction of the term cyberspace into the legal language. The article raises issues connected with the indefiniteness of the term cyberspace, presents reflections involving the necessity of differentiation and defining of terms such as: cyberspace, virtual space, virtual reality, artificial reality, etc. These terms are sometimes used interchangeably, it is difficult to control the conceptual chaos with which we deal within the sphere of modern technologies. Attention is also drawn to the possible necessity of changing the notion of country's territory in the context of the country's functioning in cyberspace. The author also stipulates the necessity of discussing the definitions of phenomena occurring within the sphere of modern technologies with specialists in the field of technical, sociological, psychological studies, before they are introduced into the legal language. The article doubts whether the term cyberspace should have been introduced into the legal language at all. The author suggests that it should have been taken under consideration whether the possibility of another form of dealing with the issue of such dangers exists, such as dangers of the country's cyberspace. It is also questioned whether the introduced definition of cyberspace will prove to be a universal definition for the whole legal system.