A sensor device is equipped with a housing having an element cover retaining a sensor element such that a detection section of the sensor element is positioned at the tip end of the sensor element. The element cover includes an inner cover provided with inner side holes and an inner tip face hole respectively provided therein, and an outer cover provided with outer side holes in a side thereof, with the tip position of the outer side holes located closer to the tip end than is the tip position of the inner cover. Between the outer surface of the inner cover and the inner surface of the outer cover there is a large clearance section at the tip end and a small clearance section at the base end, providing a flow path that is shaped for connecting the large clearance section and the small clearance section without a step.