We investigate the possibility of finding evidence for planets in circumstellar disks by infrared and submillimeter interferometry. We present simulations of a circumstellar disk around a solar-type star with an embedded planet of 1 Jupiter mass. The three-dimensional density structure of the disk results from hydrodynamical simulations. On the basis of three-dimensional radiative transfer simulations, images of this system were calculated. The intensity maps provide the basis for the simulation of the Very Large Telescope Interferometer (VLTI; equipped with the mid-infrared instrument MIDI) and the Atacama Large Millimeter Array (ALMA). While MIDI/VLTI will not provide the possibility to distinguish between disks with or without a gap on the basis of visibility measurements, ALMA will provide the necessary basis for a direct gap detection.