A pressure sensor includes a substrate, a patterned circuit, and a conductive material layer. The patterned circuit, formed on the substrate, includes a first-path part and a second-path part of which at least a part is formed at a predetermined gap from at least a part of the first-path part. The conductive material layer, resiliently disposed on the patterned circuit, has protrusions. The conductive material layer deforms to determine a contact area between the protrusions and the substrate, and upon deformation of the conductive material layer to contact the first-path part, the gap between the first-path part and the second-path part, and the second-path part, the first-path part electrically connects to the second-path part.