This text is about research into the use of multi-media techniques in Biology lessons of fifth and sixth form classes to develop the classes`experimental abilities. The aim of this teaching unit was to develop and improve the experimental knowledge, abilities and skills of the 80 involved students, who mainly worked inquiringly on the solution to the problem. The experimental abilities and skills have been divided into three different levels, which make it easier to assess the qualitiy of the students`knowledge. Using multi-media techniques, the level of their independent experimentation has been increased in the fields of preparing an experiment, performing an experiment and analysing an experiment. This examination proved the thesis that the majority of the students had basic experimental competence, but they were unable to use it to the required level three. The interpretation of the research data proves that the students'experimental knowledge has improved, especially their abilities on the third level of competence. The results show that the students have been enabled to work and think scientifically and to use their knowledge independently. The use of multi-media techniques offers various possibilities to increase the level of the preparation, performance and analysis of students'experiments. Experimental Biology lessons, in wich multi-media techniques are used, also help to improve the abilities of the students to work with the media. Having analysed the knowledge of the students before and after this teaching unit with the help of the Wilcoxon test I come to the conclusion that the students are significantly better at PC presentations, at performing digital methods of measurement and at working with reading programmes.