In our days physical sciences and museum education are a part of preschool education. So this research is focused on the creation of educational material for the Natural History Museum of Lesvos’ Petrified Forest, which could be used by pre-school children. First, preschool children’s perceptions about the Petrified Forest are investigated, through interviews. An intervention follows, based on chosen material of the museum kits. And at the third stage of this research, interviews are repeated in order to investigate if the intervention had such results that the children changed their previous conceptions (misconceptions). The results of the research indicated that children’s ideas changed towards more scientific ones. Based on the results, new educational material is suggested that can constitute a new museum kit, which will consist of elements of the previous ones and additional material, so that it will meet the level and abilities of preschool children.