PURPOSE: To eliminate negative effect of a land/underwater mine after an end of a dispute by employing the land/underwater mine having a time inactivating system and have a society having thickly grown greens by use of seeds arranged in the land/underwater mine having the time inactivating system.

CONSTITUTION: In a detonator and an explosive for a land/underwater mine and the like, the function of the land/underwater mine and the like is inactivated by means of a time inactivating system after the elapse of a certain period of a certain period of time, e.g. after a period of 6 months to a year, from the time of setting the mine and the like in such a manner as to function as an explosive. The system has seeds of trees arranged within so that the seeds germinate and the trees grow thick, with the mine being inactivated. Because the land/underwater mine and the like do not function as an explosive after the elapse of a certain period of time, negative effect of the buried mine after an end of a dispute is completely eliminated and positive effect of planting trees is obtained by thickly growing trees.