Disclosed is a lead-free low softening point glass whose composition lies within the system SnO--P.sub.2O.sub.5 and containing over 5 to 30 mol % of MnO. The addition of MnO allows the water resistance and coefficient of thermal expansion of the glass to be improved without spoiling its feature of a low softening point. The lead-free low softening point glass can be prepared through a simplified production process.