An acceleration sensor capable of restraining a reduction in output thereof due to an electrostatic capacity between acceleration detecting electrodes and output electrodes. A low-dielectric layer is arranged between a connection line and a piezoelectric ceramic substrate. Another low-dielectric layer is arranged between additional connection lines and output electrodes, and the substrate. The low-dielectric layers are formed of a material substantially reduced in relative dielectric constant as compared with the substrate. The low-dielectric layers reduce an electrostatic capacity generated between wiring patterns and the output electrodes, and a counter electrode pattern, to thereby reduce the amount of spontaneous polarization charges accumulated in the electrostatic capacity.