To provide a pest insect trap which can maintain the capture performance of pest insects by an adhesive sheet over a long period of time when used in a farm requiring capturing of pest insects, particularly, an agricultural field in which soil dust, sand dust, litter or the like flies due to air flows, and is excellent in usability.

The pest insect trap includes: a bar-like strut portion 1 fixed in an installation place; a holding portion 2 having a columnar body 21 and an intermediate hole 22 formed to extend from the lower end to a predetermined intermediate position along the center line of the body, the holding portion being rotatably and detachably supported by a tip of the strut portion 1 inserted to the intermediate hole 22 on a ceiling wall 22a of the intermediate hole 22; an adhesive sheet portion 3 having a substrate 31 and an adhesive layer 32 formed on the substrate 31, the sheet portion capturing attracted pest insects by the adhesive layer; and an attachment portion 4 for attaching the adhesive sheet portion 3 to the holding portion 2 along the center line direction of the body 21 of the holding portion 2. The installation position of the adhesive sheet portion 3 can be changed in a direction parallel to a direction of air flow by rotating the adhesive sheet portion 3 around the strut portion 1.