In order to attain the widest implementation for ocean education throughout Japan, we need to develop educational materials performable in all the schools including those in land-locked areas. Such materials must meet the following three criteria: (1) it meets the request that the ocean should be taught naturally and unconstrainedly, particularly in schools where students cannot see the sea in their daily life, (2) it is relevant to curriculum, and (3) it requires little space and cost. In this article I will introduce one example of such materials, with which students can easily exercise salt making using an evapolation plate and a small amount of seawater in an elementary school science classroom.