A micromechanical sensor device and manufacturing method. The micromechanical sensor device is provided with a cap substrate, which has a first front side and a first back side, and which has a through-opening as a media entry region; and with a sensor substrate, which has a second front side and a second back side, and which has, on the second front side, a sensor region that is embedded in an island-like region suspended on the remaining sensor substrate. The island-like region is mechanically decoupled from the remaining sensor substrate by a lateral stress-relief trench and by a cavity situated in the sensor substrate, underneath the island-like region. The first back side is bonded to the second front side so that the through opening is situated above the sensor region. The sensor region is covered by a gel, which fills the through-opening and the stress-relief trench at least partially.