Provided is a capacitive electromechanical transducer manufactured by fusion bonding, which is capable of enhancing the performance by reducing fluctuations in initial deformation among diaphragms caused at positions having difference boundary conditions such as the bonding area. The capacitive electromechanical transducer includes a device, the device including at least one cellular structure including: a silicon substrate; a diaphragm; and a diaphragm supporting portion configured to support the diaphragm so that a gap is formed between one surface of the silicon substrate and the diaphragm. The device has, in its periphery, a groove formed in a layer shared with the diaphragm supporting portion.