Disclosed herein an inertial sensor and a method of manufacturing the same. An inertial sensor 100 according to a preferred embodiment of the present invention is configured to include a plate-shaped membrane 110, a mass body 120 that includes an adhesive part 123 disposed under a central portion 113 of the membrane 110 and provided at the central portion thereof and a patterning part 125 provided at an outer side of the adhesive part 123 and patterned to vertically penetrate therethrough, and a first adhesive layer 130 that is formed between the membrane 110 and the adhesive part 123 and is provided at an inner side of the patterning part 125. An area of the first adhesive layer 130 is narrow by isotropic etching using the patterning part 125 as a mask, thereby making it possible to improve sensitivity of the inertial sensor 100.