The invention is intended to provide an excavation teaching device for a construction machine which can realize easy confirmation of a proper target excavation surface and increase the working efficiency during excavation even in work of forming the face of slope in complicated three-dimensional landforms. A display unit (46) displays, as an image in a first screen area (46a), a plurality of small plane surfaces G constituting a three-dimensional target landform and illustrations of a body S of the construction machine and a bucket B as an excavating tool at a fore end of an operating mechanism.