PURPOSE: To easily obtain the titled compound having excellent absorbability in vegetables used as a remedy for cancer, etc., by reacting an alkali metal germanate with an organic complexing agent.

CONSTITUTION: The objective compound can be produced by reacting 1mol of an alkali metal germanate with preferably ≥4 base equivalent of an organic complexing agent (e.g. ethylenediamine-N,N'-tetraacetic acid) preferably under heating. The alkali metal germanate is obtained e.g. by boiling germanium oxide and an alkali such as sodium hydroxide in water.