This paper reports on a microspectrometer using a concave grating fabricated in a MEMS compatible process. The fabrication technique is based on a standard lithography commonly used for pattern transfer onto a flat substrate. A planar grating structure is fabricated lithographically on top of a flexible membrane on a glass or silicon wafer and the membrane is subsequently deformed into a pre-defined shape using a master. The proposed technology had been used for the fabrication of the concave gratings for a microspectrometer composed of entrance slit, grating and image sensor. The fabricated microspectrometer demonstrates a subnanometer spectral resolution.