The molecular parameters of digermane have been determined by gas-phase electron diffraction. The bond lengths (rg(1) values) are Ge—H = 1.541±0.006 Å, Ge—Ge = 2.403±0.003 Å, and ∠HGeH = 106.4±0.8°. The Ge—Ge length is 0.046 Å shorter than the value found in solid germanium.