To provide a nest box for ladybug designed to breed ladybug as a kind of beneficial insect based on its habit, thus protecting a safe environment using no agrochemicals by eating and exterminating insect pests adhering to plants by the ladybug.

The nest box for ladybug is such that: there are a number of openings so as to be usable for a number of ladybug and each of them is processed oblongly and made in the form of a round hole 8 mm in both diameter and height; a leg part integrated with the nest box is easily detachable and can be loaded/unloaded with withered leaves and twigs in conformity with the surroundings and/or season's circumstances; besides, the leg part is directly inserted into the ground and can easily be installed at a height of 20-60 cm above the ground for ladybug to do activities.