A sensor with a chamber comprises a base, a cavity body, a sensing element, and a porous gel material. The cavity body is disposed on the base and has a cavity wall and an inner space formed inside the cavity wall, the sensing element is disposed on the cavity wall, and the porous gel material is disposed between the base and the cavity body, the porous gel material has a porosity of not less than 80%, so that gas is capable of communicating between the inner space of the cavity body and an outside, thereby forming a passage for gas to enter and exit to balance a pressure in the sensor with the chamber, increase a support of the sensor with the chamber, and reduce the risk of conventional bonding between the sensing element and the base using die-bonding adhesive.