To preserve hemipterous insects without degrading their quality by making the insects coexistent with a cushioning material and water in a closed space and by maintaining the closed space at temperatures within a specified range.

Hemipterous insects 3 are preserved by making them coexistent with a cushioning material 2 and water in a closed space and by maintaining the closed space at about 0-10°C; wherein the closed space can be afforded by a closed vessel, the cushioning material 2 may be vermiculite; furthermore it is preferable that the water to be present is at 1-40 vol.% based on the cushioning material 2; and the hemipterous insects 3 include those belonging to Deltocephalidae, Delphacidae, Aphididae and Pentatomidae.