High performance accelerometers have wide variety of applications in inertial navigation, seismic imaging, and conditional health monitoring. This paper reports mechanical design, fabrication, and characterization of an in-plane MEMS accelerometer. The sensor has been designed in such a way to meet both the high sensitivity and the wide bandwidth requirements in one single device. The MEMS sensor, which is an interdigitated capacitive accelerometer, is fabricated from a 100 um thick SOI wafer using deep reactive ion etching (DRIE) process. Theoretical results were confirmed by experimental measurements. Sensor has a resonance frequency at 2.3 KHz. Voltage sensitivity of the device is 11.8mV/g. The mechanical-thermal noise of the device is 193ng/rtHz. These characteristics make the device a promising candidate for applications where both the high sensitivity and the wide bandwidth are required.